/*

Simple DirectMedia Layer

Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>

This software is provided 'as-is', without any express or implied

warranty. In no event will the authors be held liable for any damages

arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not

claim that you wrote the original software. If you use this software

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

2. Altered source versions must be plainly marked as such, and must not be

misrepresented as being the original software.

3. This notice may not be removed or altered from any source distribution.

*/

#include "../../SDL_internal.h"

#if SDL_VIDEO_RENDER_METAL && !SDL_RENDER_DISABLED

#include "SDL_hints.h"

#include "SDL_log.h"

#include "SDL_assert.h"

#include "SDL_syswm.h"

#include "../SDL_sysrender.h"

#ifdef __MACOSX__

#include "../../video/cocoa/SDL_cocoametalview.h"

#else

#include "../../video/uikit/SDL_uikitmetalview.h"

#endif

#import <Metal/Metal.h>

#import <QuartzCore/CAMetalLayer.h>

/* Regenerate these with build-metal-shaders.sh */

#ifdef __MACOSX__

#include "SDL_shaders_metal_osx.h"

#else

#include "SDL_shaders_metal_ios.h"

#endif

/* Apple Metal renderer implementation */

static SDL_Renderer *METAL_CreateRenderer(SDL_Window * window, Uint32 flags);

static void METAL_WindowEvent(SDL_Renderer * renderer,

const SDL_WindowEvent *event);

static int METAL_GetOutputSize(SDL_Renderer * renderer, int *w, int *h);

static SDL_bool METAL_SupportsBlendMode(SDL_Renderer * renderer, SDL_BlendMode blendMode);

static int METAL_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture);

static int METAL_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * rect, const void *pixels,

int pitch);

static int METAL_UpdateTextureYUV(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * rect,

const Uint8 *Yplane, int Ypitch,

const Uint8 *Uplane, int Upitch,

const Uint8 *Vplane, int Vpitch);

static int METAL_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * rect, void **pixels, int *pitch);

static void METAL_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture);

static int METAL_SetRenderTarget(SDL_Renderer * renderer, SDL_Texture * texture);

static int METAL_UpdateViewport(SDL_Renderer * renderer);

static int METAL_UpdateClipRect(SDL_Renderer * renderer);

static int METAL_RenderClear(SDL_Renderer * renderer);

static int METAL_RenderDrawPoints(SDL_Renderer * renderer,

const SDL_FPoint * points, int count);

static int METAL_RenderDrawLines(SDL_Renderer * renderer,

const SDL_FPoint * points, int count);

static int METAL_RenderFillRects(SDL_Renderer * renderer,

const SDL_FRect * rects, int count);

static int METAL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * srcrect, const SDL_FRect * dstrect);

static int METAL_RenderCopyEx(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * srcrect, const SDL_FRect * dstrect,

const double angle, const SDL_FPoint *center, const SDL_RendererFlip flip);

static int METAL_RenderReadPixels(SDL_Renderer * renderer, const SDL_Rect * rect,

Uint32 pixel_format, void * pixels, int pitch);

static void METAL_RenderPresent(SDL_Renderer * renderer);

static void METAL_DestroyTexture(SDL_Renderer * renderer, SDL_Texture * texture);

static void METAL_DestroyRenderer(SDL_Renderer * renderer);

static void *METAL_GetMetalLayer(SDL_Renderer * renderer);

static void *METAL_GetMetalCommandEncoder(SDL_Renderer * renderer);

SDL_RenderDriver METAL_RenderDriver = {

METAL_CreateRenderer,

{

"metal",

(SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_TARGETTEXTURE),

2,

{SDL_PIXELFORMAT_ARGB8888, SDL_PIXELFORMAT_ABGR8888},

// !!! FIXME: how do you query Metal for this?

// (the weakest GPU supported by Metal on iOS has 4k texture max, and

// other models might be 2x or 4x more. On macOS, it's 16k across the

// board right now.)

#ifdef __MACOSX__

16384, 16384

#else

4096, 4096

#endif

}

};

typedef enum SDL_MetalVertexFunction

{

SDL_METAL_VERTEX_SOLID,

SDL_METAL_VERTEX_COPY,

} SDL_MetalVertexFunction;

typedef enum SDL_MetalFragmentFunction

{

SDL_METAL_FRAGMENT_SOLID,

SDL_METAL_FRAGMENT_COPY,

} SDL_MetalFragmentFunction;

typedef struct METAL_PipelineState

{

SDL_BlendMode blendMode;

void *pipe;

} METAL_PipelineState;

typedef struct METAL_PipelineCache

{

METAL_PipelineState *states;

int count;

SDL_MetalVertexFunction vertexFunction;

SDL_MetalFragmentFunction fragmentFunction;

const char *label;

} METAL_PipelineCache;

@interface METAL_RenderData : NSObject

@property (nonatomic, assign) BOOL beginScene;

@property (nonatomic, retain) id<MTLDevice> mtldevice;

@property (nonatomic, retain) id<MTLCommandQueue> mtlcmdqueue;

@property (nonatomic, retain) id<MTLCommandBuffer> mtlcmdbuffer;

@property (nonatomic, retain) id<MTLRenderCommandEncoder> mtlcmdencoder;

@property (nonatomic, retain) id<MTLLibrary> mtllibrary;

@property (nonatomic, retain) id<CAMetalDrawable> mtlbackbuffer;

@property (nonatomic, assign) METAL_PipelineCache *mtlpipelineprims;

@property (nonatomic, assign) METAL_PipelineCache *mtlpipelinecopy;

@property (nonatomic, retain) id<MTLSamplerState> mtlsamplernearest;

@property (nonatomic, retain) id<MTLSamplerState> mtlsamplerlinear;

@property (nonatomic, retain) id<MTLBuffer> mtlbufclearverts;

@property (nonatomic, retain) id<MTLBuffer> mtlbufidentitytransform;

@property (nonatomic, retain) CAMetalLayer *mtllayer;

@property (nonatomic, retain) MTLRenderPassDescriptor *mtlpassdesc;

@end

@implementation METAL_RenderData

#if !__has_feature(objc_arc)

- (void)dealloc

{

[_mtldevice release];

[_mtlcmdqueue release];

[_mtlcmdbuffer release];

[_mtlcmdencoder release];

[_mtllibrary release];

[_mtlbackbuffer release];

[_mtlsamplernearest release];

[_mtlsamplerlinear release];

[_mtlbufclearverts release];

[_mtlbufidentitytransform release];

[_mtllayer release];

[_mtlpassdesc release];

[super dealloc];

}

#endif

@end

@interface METAL_TextureData : NSObject

@property (nonatomic, retain) id<MTLTexture> mtltexture;

@property (nonatomic, retain) id<MTLSamplerState> mtlsampler;

@end

@implementation METAL_TextureData

#if !__has_feature(objc_arc)

- (void)dealloc

{

[_mtltexture release];

[_mtlsampler release];

[super dealloc];

}

#endif

@end

static int

IsMetalAvailable(const SDL_SysWMinfo *syswm)

{

if (syswm->subsystem != SDL_SYSWM_COCOA && syswm->subsystem != SDL_SYSWM_UIKIT) {

return SDL_SetError("Metal render target only supports Cocoa and UIKit video targets at the moment.");

}

// this checks a weak symbol.

#if (defined(__MACOSX__) && (MAC_OS_X_VERSION_MIN_REQUIRED < 101100))

if (MTLCreateSystemDefaultDevice == NULL) { // probably on 10.10 or lower.

return SDL_SetError("Metal framework not available on this system");

}

#endif

return 0;

}

static const MTLBlendOperation invalidBlendOperation = (MTLBlendOperation)0xFFFFFFFF;

static const MTLBlendFactor invalidBlendFactor = (MTLBlendFactor)0xFFFFFFFF;

static MTLBlendOperation

GetBlendOperation(SDL_BlendOperation operation)

{

switch (operation) {

case SDL_BLENDOPERATION_ADD: return MTLBlendOperationAdd;

case SDL_BLENDOPERATION_SUBTRACT: return MTLBlendOperationSubtract;

case SDL_BLENDOPERATION_REV_SUBTRACT: return MTLBlendOperationReverseSubtract;

case SDL_BLENDOPERATION_MINIMUM: return MTLBlendOperationMin;

case SDL_BLENDOPERATION_MAXIMUM: return MTLBlendOperationMax;

default: return invalidBlendOperation;

}

}

static MTLBlendFactor

GetBlendFactor(SDL_BlendFactor factor)

{

switch (factor) {

case SDL_BLENDFACTOR_ZERO: return MTLBlendFactorZero;

case SDL_BLENDFACTOR_ONE: return MTLBlendFactorOne;

case SDL_BLENDFACTOR_SRC_COLOR: return MTLBlendFactorSourceColor;

case SDL_BLENDFACTOR_ONE_MINUS_SRC_COLOR: return MTLBlendFactorOneMinusSourceColor;

case SDL_BLENDFACTOR_SRC_ALPHA: return MTLBlendFactorSourceAlpha;

case SDL_BLENDFACTOR_ONE_MINUS_SRC_ALPHA: return MTLBlendFactorOneMinusSourceAlpha;

case SDL_BLENDFACTOR_DST_COLOR: return MTLBlendFactorDestinationColor;

case SDL_BLENDFACTOR_ONE_MINUS_DST_COLOR: return MTLBlendFactorOneMinusDestinationColor;

case SDL_BLENDFACTOR_DST_ALPHA: return MTLBlendFactorDestinationAlpha;

case SDL_BLENDFACTOR_ONE_MINUS_DST_ALPHA: return MTLBlendFactorOneMinusDestinationAlpha;

default: return invalidBlendFactor;

}

}

static NSString *

GetVertexFunctionName(SDL_MetalVertexFunction function)

{

switch (function) {

case SDL_METAL_VERTEX_SOLID: return @"SDL_Solid_vertex";

case SDL_METAL_VERTEX_COPY: return @"SDL_Copy_vertex";

default: return nil;

}

}

static NSString *

GetFragmentFunctionName(SDL_MetalFragmentFunction function)

{

switch (function) {

case SDL_METAL_FRAGMENT_SOLID: return @"SDL_Solid_fragment";

case SDL_METAL_FRAGMENT_COPY: return @"SDL_Copy_fragment";

default: return nil;

}

}

static id<MTLRenderPipelineState>

MakePipelineState(METAL_RenderData *data, METAL_PipelineCache *cache,

NSString *blendlabel, SDL_BlendMode blendmode)

{

id<MTLFunction> mtlvertfn = [data.mtllibrary newFunctionWithName:GetVertexFunctionName(cache->vertexFunction)];

id<MTLFunction> mtlfragfn = [data.mtllibrary newFunctionWithName:GetFragmentFunctionName(cache->fragmentFunction)];

SDL_assert(mtlvertfn != nil);

SDL_assert(mtlfragfn != nil);

MTLRenderPipelineDescriptor *mtlpipedesc = [[MTLRenderPipelineDescriptor alloc] init];

mtlpipedesc.vertexFunction = mtlvertfn;

mtlpipedesc.fragmentFunction = mtlfragfn;

MTLRenderPipelineColorAttachmentDescriptor *rtdesc = mtlpipedesc.colorAttachments[0];

// !!! FIXME: This should be part of the pipeline state cache.

rtdesc.pixelFormat = data.mtllayer.pixelFormat;

if (blendmode != SDL_BLENDMODE_NONE) {

rtdesc.blendingEnabled = YES;

rtdesc.sourceRGBBlendFactor = GetBlendFactor(SDL_GetBlendModeSrcColorFactor(blendmode));

rtdesc.destinationRGBBlendFactor = GetBlendFactor(SDL_GetBlendModeDstColorFactor(blendmode));

rtdesc.rgbBlendOperation = GetBlendOperation(SDL_GetBlendModeColorOperation(blendmode));

rtdesc.sourceAlphaBlendFactor = GetBlendFactor(SDL_GetBlendModeSrcAlphaFactor(blendmode));

rtdesc.destinationAlphaBlendFactor = GetBlendFactor(SDL_GetBlendModeDstAlphaFactor(blendmode));

rtdesc.alphaBlendOperation = GetBlendOperation(SDL_GetBlendModeAlphaOperation(blendmode));

} else {

rtdesc.blendingEnabled = NO;

}

mtlpipedesc.label = [@(cache->label) stringByAppendingString:blendlabel];

NSError *err = nil;

id<MTLRenderPipelineState> state = [data.mtldevice newRenderPipelineStateWithDescriptor:mtlpipedesc error:&err];

SDL_assert(err == nil);

METAL_PipelineState pipeline;

pipeline.blendMode = blendmode;

pipeline.pipe = (void *)CFBridgingRetain(state);

METAL_PipelineState *states = SDL_realloc(cache->states, (cache->count + 1) * sizeof(pipeline));

#if !__has_feature(objc_arc)

[mtlpipedesc release]; // !!! FIXME: can these be reused for each creation, or does the pipeline obtain it?

[mtlvertfn release];

[mtlfragfn release];

[state release];

#endif

if (states) {

states[cache->count++] = pipeline;

cache->states = states;

return (__bridge id<MTLRenderPipelineState>)pipeline.pipe;

} else {

CFBridgingRelease(pipeline.pipe);

SDL_OutOfMemory();

return NULL;

}

}

static METAL_PipelineCache *

MakePipelineCache(METAL_RenderData *data, const char *label, SDL_MetalVertexFunction vertfn, SDL_MetalFragmentFunction fragfn)

{

METAL_PipelineCache *cache = SDL_malloc(sizeof(METAL_PipelineCache));

if (!cache) {

SDL_OutOfMemory();

return NULL;

}

SDL_zerop(cache);

cache->vertexFunction = vertfn;

cache->fragmentFunction = fragfn;

cache->label = label;

/* Create pipeline states for the default blend modes. Custom blend modes

* will be added to the cache on-demand. */

MakePipelineState(data, cache, @"(blend=none)", SDL_BLENDMODE_NONE);

MakePipelineState(data, cache, @"(blend=blend)", SDL_BLENDMODE_BLEND);

MakePipelineState(data, cache, @"(blend=add)", SDL_BLENDMODE_ADD);

MakePipelineState(data, cache, @"(blend=mod)", SDL_BLENDMODE_MOD);

return cache;

}

static void

DestroyPipelineCache(METAL_PipelineCache *cache)

{

if (cache != NULL) {

for (int i = 0; i < cache->count; i++) {

CFBridgingRelease(cache->states[i].pipe);

}

SDL_free(cache->states);

SDL_free(cache);

}

}

static inline id<MTLRenderPipelineState>

ChoosePipelineState(METAL_RenderData *data, METAL_PipelineCache *cache, const SDL_BlendMode blendmode)

{

for (int i = 0; i < cache->count; i++) {

if (cache->states[i].blendMode == blendmode) {

return (__bridge id<MTLRenderPipelineState>)cache->states[i].pipe;

}

}

return MakePipelineState(data, cache, [NSString stringWithFormat:@"(blend=custom 0x%x)", blendmode], blendmode);

}

static SDL_Renderer *

METAL_CreateRenderer(SDL_Window * window, Uint32 flags)

{

SDL_Renderer *renderer = NULL;

METAL_RenderData *data = NULL;

SDL_SysWMinfo syswm;

SDL_VERSION(&syswm.version);

if (!SDL_GetWindowWMInfo(window, &syswm)) {

return NULL;

}

if (IsMetalAvailable(&syswm) == -1) {

return NULL;

}

renderer = (SDL_Renderer *) SDL_calloc(1, sizeof(*renderer));

if (!renderer) {

SDL_OutOfMemory();

return NULL;

}

data = [[METAL_RenderData alloc] init];

data.beginScene = YES;

renderer->driverdata = (void*)CFBridgingRetain(data);

renderer->window = window;

#ifdef __MACOSX__

id<MTLDevice> mtldevice = MTLCreateSystemDefaultDevice(); // !!! FIXME: MTLCopyAllDevices() can find other GPUs...

if (mtldevice == nil) {

SDL_free(renderer);

#if !__has_feature(objc_arc)

[data release];

#endif

SDL_SetError("Failed to obtain Metal device");

return NULL;

}

// !!! FIXME: error checking on all of this.

NSView *view = Cocoa_Mtl_AddMetalView(window);

CAMetalLayer *layer = (CAMetalLayer *)[view layer];

layer.device = mtldevice;

//layer.colorspace = nil;

#else

UIView *view = UIKit_Mtl_AddMetalView(window);

CAMetalLayer *layer = (CAMetalLayer *)[view layer];

#endif

// Necessary for RenderReadPixels.

layer.framebufferOnly = NO;

data.mtldevice = layer.device;

data.mtllayer = layer;

id<MTLCommandQueue> mtlcmdqueue = [data.mtldevice newCommandQueue];

data.mtlcmdqueue = mtlcmdqueue;

data.mtlcmdqueue.label = @"SDL Metal Renderer";

data.mtlpassdesc = [MTLRenderPassDescriptor renderPassDescriptor];

NSError *err = nil;

// The compiled .metallib is embedded in a static array in a header file

// but the original shader source code is in SDL_shaders_metal.metal.

dispatch_data_t mtllibdata = dispatch_data_create(sdl_metallib, sdl_metallib_len, dispatch_get_global_queue(0, 0), ^{});

id<MTLLibrary> mtllibrary = [data.mtldevice newLibraryWithData:mtllibdata error:&err];

data.mtllibrary = mtllibrary;

SDL_assert(err == nil);

#if !__has_feature(objc_arc)

dispatch_release(mtllibdata);

#endif

data.mtllibrary.label = @"SDL Metal renderer shader library";

data.mtlpipelineprims = MakePipelineCache(data, "SDL primitives pipeline ", SDL_METAL_VERTEX_SOLID, SDL_METAL_FRAGMENT_SOLID);

data.mtlpipelinecopy = MakePipelineCache(data, "SDL texture pipeline ", SDL_METAL_VERTEX_COPY, SDL_METAL_FRAGMENT_COPY);

MTLSamplerDescriptor *samplerdesc = [[MTLSamplerDescriptor alloc] init];

samplerdesc.minFilter = MTLSamplerMinMagFilterNearest;

samplerdesc.magFilter = MTLSamplerMinMagFilterNearest;

id<MTLSamplerState> mtlsamplernearest = [data.mtldevice newSamplerStateWithDescriptor:samplerdesc];

data.mtlsamplernearest = mtlsamplernearest;

samplerdesc.minFilter = MTLSamplerMinMagFilterLinear;

samplerdesc.magFilter = MTLSamplerMinMagFilterLinear;

id<MTLSamplerState> mtlsamplerlinear = [data.mtldevice newSamplerStateWithDescriptor:samplerdesc];

data.mtlsamplerlinear = mtlsamplerlinear;

static const float clearverts[] = { 0, 0, 0, 3, 3, 0 };

id<MTLBuffer> mtlbufclearverts = [data.mtldevice newBufferWithBytes:clearverts length:sizeof(clearverts) options:MTLResourceCPUCacheModeWriteCombined];

data.mtlbufclearverts = mtlbufclearverts;

data.mtlbufclearverts.label = @"SDL_RenderClear vertices";

float identitytx[16];

SDL_memset(identitytx, 0, sizeof(identitytx));

identitytx[0] = identitytx[5] = identitytx[10] = identitytx[15] = 1.0f;

id<MTLBuffer> mtlbufidentitytransform = [data.mtldevice newBufferWithBytes:identitytx length:sizeof(identitytx) options:0];

data.mtlbufidentitytransform = mtlbufidentitytransform;

data.mtlbufidentitytransform.label = @"SDL_RenderCopy identity transform";

// !!! FIXME: force more clears here so all the drawables are sane to start, and our static buffers are definitely flushed.

renderer->WindowEvent = METAL_WindowEvent;

renderer->GetOutputSize = METAL_GetOutputSize;

renderer->SupportsBlendMode = METAL_SupportsBlendMode;

renderer->CreateTexture = METAL_CreateTexture;

renderer->UpdateTexture = METAL_UpdateTexture;

renderer->UpdateTextureYUV = METAL_UpdateTextureYUV;

renderer->LockTexture = METAL_LockTexture;

renderer->UnlockTexture = METAL_UnlockTexture;

renderer->SetRenderTarget = METAL_SetRenderTarget;

renderer->UpdateViewport = METAL_UpdateViewport;

renderer->UpdateClipRect = METAL_UpdateClipRect;

renderer->RenderClear = METAL_RenderClear;

renderer->RenderDrawPoints = METAL_RenderDrawPoints;

renderer->RenderDrawLines = METAL_RenderDrawLines;

renderer->RenderFillRects = METAL_RenderFillRects;

renderer->RenderCopy = METAL_RenderCopy;

renderer->RenderCopyEx = METAL_RenderCopyEx;

renderer->RenderReadPixels = METAL_RenderReadPixels;

renderer->RenderPresent = METAL_RenderPresent;

renderer->DestroyTexture = METAL_DestroyTexture;

renderer->DestroyRenderer = METAL_DestroyRenderer;

renderer->GetMetalLayer = METAL_GetMetalLayer;

renderer->GetMetalCommandEncoder = METAL_GetMetalCommandEncoder;

renderer->info = METAL_RenderDriver.info;

renderer->info.flags = (SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE);

#if defined(__MACOSX__) && defined(MAC_OS_X_VERSION_10_13)

if (@available(macOS 10.13, *)) {

data.mtllayer.displaySyncEnabled = (flags & SDL_RENDERER_PRESENTVSYNC) != 0;

} else

#endif

{

renderer->info.flags |= SDL_RENDERER_PRESENTVSYNC;

}

#if !__has_feature(objc_arc)

[mtlcmdqueue release];

[mtllibrary release];

[samplerdesc release];

[mtlsamplernearest release];

[mtlsamplerlinear release];

[mtlbufclearverts release];

[mtlbufidentitytransform release];

[view release];

[data release];

#ifdef __MACOSX__

[mtldevice release];

#endif

#endif

return renderer;

}

static void

METAL_ActivateRenderer(SDL_Renderer * renderer)

{

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

if (data.beginScene) {

data.beginScene = NO;

data.mtlbackbuffer = [data.mtllayer nextDrawable];

SDL_assert(data.mtlbackbuffer);

data.mtlpassdesc.colorAttachments[0].texture = data.mtlbackbuffer.texture;

data.mtlpassdesc.colorAttachments[0].loadAction = MTLLoadActionDontCare;

data.mtlcmdbuffer = [data.mtlcmdqueue commandBuffer];

data.mtlcmdencoder = [data.mtlcmdbuffer renderCommandEncoderWithDescriptor:data.mtlpassdesc];

data.mtlcmdencoder.label = @"SDL metal renderer start of frame";

// Set up our current renderer state for the next frame...

METAL_UpdateViewport(renderer);

METAL_UpdateClipRect(renderer);

}

}

static void

METAL_WindowEvent(SDL_Renderer * renderer, const SDL_WindowEvent *event)

{

if (event->event == SDL_WINDOWEVENT_SIZE_CHANGED ||

event->event == SDL_WINDOWEVENT_SHOWN ||

event->event == SDL_WINDOWEVENT_HIDDEN) {

// !!! FIXME: write me

}

}

static int

METAL_GetOutputSize(SDL_Renderer * renderer, int *w, int *h)

{ @autoreleasepool {

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

if (w) {

*w = (int)data.mtllayer.drawableSize.width;

}

if (h) {

*h = (int)data.mtllayer.drawableSize.height;

}

return 0;

}}

static SDL_bool

METAL_SupportsBlendMode(SDL_Renderer * renderer, SDL_BlendMode blendMode)

{

SDL_BlendFactor srcColorFactor = SDL_GetBlendModeSrcColorFactor(blendMode);

SDL_BlendFactor srcAlphaFactor = SDL_GetBlendModeSrcAlphaFactor(blendMode);

SDL_BlendOperation colorOperation = SDL_GetBlendModeColorOperation(blendMode);

SDL_BlendFactor dstColorFactor = SDL_GetBlendModeDstColorFactor(blendMode);

SDL_BlendFactor dstAlphaFactor = SDL_GetBlendModeDstAlphaFactor(blendMode);

SDL_BlendOperation alphaOperation = SDL_GetBlendModeAlphaOperation(blendMode);

if (GetBlendFactor(srcColorFactor) == invalidBlendFactor ||

GetBlendFactor(srcAlphaFactor) == invalidBlendFactor ||

GetBlendOperation(colorOperation) == invalidBlendOperation ||

GetBlendFactor(dstColorFactor) == invalidBlendFactor ||

GetBlendFactor(dstAlphaFactor) == invalidBlendFactor ||

GetBlendOperation(alphaOperation) == invalidBlendOperation) {

return SDL_FALSE;

}

return SDL_TRUE;

}

static int

METAL_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture)

{ @autoreleasepool {

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

MTLPixelFormat mtlpixfmt;

switch (texture->format) {

case SDL_PIXELFORMAT_ABGR8888: mtlpixfmt = MTLPixelFormatRGBA8Unorm; break;

case SDL_PIXELFORMAT_ARGB8888: mtlpixfmt = MTLPixelFormatBGRA8Unorm; break;

default: return SDL_SetError("Texture format %s not supported by Metal", SDL_GetPixelFormatName(texture->format));

}

MTLTextureDescriptor *mtltexdesc = [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:mtlpixfmt

width:(NSUInteger)texture->w height:(NSUInteger)texture->h mipmapped:NO];

if (texture->access == SDL_TEXTUREACCESS_TARGET) {

mtltexdesc.usage = MTLTextureUsageShaderRead | MTLTextureUsageRenderTarget;

} else {

mtltexdesc.usage = MTLTextureUsageShaderRead;

}

//mtltexdesc.resourceOptions = MTLResourceCPUCacheModeDefaultCache | MTLResourceStorageModeManaged;

//mtltexdesc.storageMode = MTLStorageModeManaged;

id<MTLTexture> mtltexture = [data.mtldevice newTextureWithDescriptor:mtltexdesc];

if (mtltexture == nil) {

return SDL_SetError("Texture allocation failed");

}

METAL_TextureData *texturedata = [[METAL_TextureData alloc] init];

const char *hint = SDL_GetHint(SDL_HINT_RENDER_SCALE_QUALITY);

if (!hint || *hint == '0' || SDL_strcasecmp(hint, "nearest") == 0) {

texturedata.mtlsampler = data.mtlsamplernearest;

} else {

texturedata.mtlsampler = data.mtlsamplerlinear;

}

texturedata.mtltexture = mtltexture;

texture->driverdata = (void*)CFBridgingRetain(texturedata);

#if !__has_feature(objc_arc)

[texturedata release];

[mtltexture release];

#endif

return 0;

}}

static int

METAL_UpdateTexture(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * rect, const void *pixels, int pitch)

{ @autoreleasepool {

// !!! FIXME: this is a synchronous call; it doesn't return until data is uploaded in some form.

// !!! FIXME: Maybe move this off to a thread that marks the texture as uploaded and only stall the main thread if we try to

// !!! FIXME: use this texture before the marking is done? Is it worth it? Or will we basically always be uploading a bunch of

// !!! FIXME: stuff way ahead of time and/or using it immediately after upload?

id<MTLTexture> mtltexture = ((__bridge METAL_TextureData *)texture->driverdata).mtltexture;

[mtltexture replaceRegion:MTLRegionMake2D(rect->x, rect->y, rect->w, rect->h) mipmapLevel:0 withBytes:pixels bytesPerRow:pitch];

return 0;

}}

static int

METAL_UpdateTextureYUV(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * rect,

const Uint8 *Yplane, int Ypitch,

const Uint8 *Uplane, int Upitch,

const Uint8 *Vplane, int Vpitch)

{

return SDL_Unsupported(); // !!! FIXME

}

static int

METAL_LockTexture(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * rect, void **pixels, int *pitch)

{

return SDL_Unsupported(); // !!! FIXME: write me

}

static void

METAL_UnlockTexture(SDL_Renderer * renderer, SDL_Texture * texture)

{

// !!! FIXME: write me

}

static int

METAL_SetRenderTarget(SDL_Renderer * renderer, SDL_Texture * texture)

{ @autoreleasepool {

METAL_ActivateRenderer(renderer);

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

// commit the current command buffer, so that any work on a render target

// will be available to the next one we're about to queue up.

[data.mtlcmdencoder endEncoding];

[data.mtlcmdbuffer commit];

id<MTLTexture> mtltexture = texture ? ((__bridge METAL_TextureData *)texture->driverdata).mtltexture : data.mtlbackbuffer.texture;

data.mtlpassdesc.colorAttachments[0].texture = mtltexture;

// !!! FIXME: this can be MTLLoadActionDontCare for textures (not the backbuffer) if SDL doesn't guarantee the texture contents should survive.

data.mtlpassdesc.colorAttachments[0].loadAction = MTLLoadActionLoad;

data.mtlcmdbuffer = [data.mtlcmdqueue commandBuffer];

data.mtlcmdencoder = [data.mtlcmdbuffer renderCommandEncoderWithDescriptor:data.mtlpassdesc];

data.mtlcmdencoder.label = texture ? @"SDL metal renderer render texture" : @"SDL metal renderer backbuffer";

// The higher level will reset the viewport and scissor after this call returns.

return 0;

}}

static int

METAL_SetOrthographicProjection(SDL_Renderer *renderer, int w, int h)

{ @autoreleasepool {

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

float projection[4][4];

if (!w || !h) {

return 0;

}

/* Prepare an orthographic projection */

projection[0][0] = 2.0f / w;

projection[0][1] = 0.0f;

projection[0][2] = 0.0f;

projection[0][3] = 0.0f;

projection[1][0] = 0.0f;

projection[1][1] = -2.0f / h;

projection[1][2] = 0.0f;

projection[1][3] = 0.0f;

projection[2][0] = 0.0f;

projection[2][1] = 0.0f;

projection[2][2] = 0.0f;

projection[2][3] = 0.0f;

projection[3][0] = -1.0f;

projection[3][1] = 1.0f;

projection[3][2] = 0.0f;

projection[3][3] = 1.0f;

// !!! FIXME: This should be in a buffer...

[data.mtlcmdencoder setVertexBytes:projection length:sizeof(float)*16 atIndex:2];

return 0;

}}

static int

METAL_UpdateViewport(SDL_Renderer * renderer)

{ @autoreleasepool {

METAL_ActivateRenderer(renderer);

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

MTLViewport viewport;

viewport.originX = renderer->viewport.x;

viewport.originY = renderer->viewport.y;

viewport.width = renderer->viewport.w;

viewport.height = renderer->viewport.h;

viewport.znear = 0.0;

viewport.zfar = 1.0;

[data.mtlcmdencoder setViewport:viewport];

METAL_SetOrthographicProjection(renderer, renderer->viewport.w, renderer->viewport.h);

return 0;

}}

static int

METAL_UpdateClipRect(SDL_Renderer * renderer)

{ @autoreleasepool {

METAL_ActivateRenderer(renderer);

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

MTLScissorRect mtlrect;

// !!! FIXME: should this care about the viewport?

if (renderer->clipping_enabled) {

const SDL_Rect *rect = &renderer->clip_rect;

mtlrect.x = renderer->viewport.x + rect->x;

mtlrect.y = renderer->viewport.x + rect->y;

mtlrect.width = rect->w;

mtlrect.height = rect->h;

} else {

mtlrect.x = renderer->viewport.x;

mtlrect.y = renderer->viewport.y;

mtlrect.width = renderer->viewport.w;

mtlrect.height = renderer->viewport.h;

}

if (mtlrect.width > 0 && mtlrect.height > 0) {

[data.mtlcmdencoder setScissorRect:mtlrect];

}

return 0;

}}

static int

METAL_RenderClear(SDL_Renderer * renderer)

{ @autoreleasepool {

// We could dump the command buffer and force a clear on a new one, but this will respect the scissor state.

METAL_ActivateRenderer(renderer);

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

// !!! FIXME: render color should live in a dedicated uniform buffer.

const float color[4] = { ((float)renderer->r) / 255.0f, ((float)renderer->g) / 255.0f, ((float)renderer->b) / 255.0f, ((float)renderer->a) / 255.0f };

MTLViewport viewport; // RenderClear ignores the viewport state, though, so reset that.

viewport.originX = viewport.originY = 0.0;

viewport.width = data.mtlpassdesc.colorAttachments[0].texture.width;

viewport.height = data.mtlpassdesc.colorAttachments[0].texture.height;

viewport.znear = 0.0;

viewport.zfar = 1.0;

// Draw a simple filled fullscreen triangle now.

METAL_SetOrthographicProjection(renderer, 1, 1);

[data.mtlcmdencoder setViewport:viewport];

[data.mtlcmdencoder setRenderPipelineState:ChoosePipelineState(data, data.mtlpipelineprims, SDL_BLENDMODE_NONE)];

[data.mtlcmdencoder setVertexBuffer:data.mtlbufclearverts offset:0 atIndex:0];

[data.mtlcmdencoder setFragmentBytes:color length:sizeof(color) atIndex:0];

[data.mtlcmdencoder drawPrimitives:MTLPrimitiveTypeTriangle vertexStart:0 vertexCount:3];

// reset the viewport for the rest of our usual drawing work...

viewport.originX = renderer->viewport.x;

viewport.originY = renderer->viewport.y;

viewport.width = renderer->viewport.w;

viewport.height = renderer->viewport.h;

viewport.znear = 0.0;

viewport.zfar = 1.0;

[data.mtlcmdencoder setViewport:viewport];

METAL_SetOrthographicProjection(renderer, renderer->viewport.w, renderer->viewport.h);

return 0;

}}

// adjust pixel center for x and y coordinates

static inline float

adjustx(const float val)

{

return (val + 0.5f);

}

static inline float

adjusty(const float val)

{

return (val + 0.5f);

}

// normalize a value from 0.0f to len into 0.0f to 1.0f.

static inline float

normtex(const float _val, const float len)

{

const float val = (_val < 0.0f) ? 0.0f : (_val > len) ? len : _val;

return ((val + 0.5f) / len);

}

static int

DrawVerts(SDL_Renderer * renderer, const SDL_FPoint * points, int count,

const MTLPrimitiveType primtype)

{ @autoreleasepool {

METAL_ActivateRenderer(renderer);

const size_t vertlen = (sizeof (float) * 2) * count;

float *verts = SDL_malloc(vertlen);

if (!verts) {

return SDL_OutOfMemory();

}

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

// !!! FIXME: render color should live in a dedicated uniform buffer.

const float color[4] = { ((float)renderer->r) / 255.0f, ((float)renderer->g) / 255.0f, ((float)renderer->b) / 255.0f, ((float)renderer->a) / 255.0f };

[data.mtlcmdencoder setRenderPipelineState:ChoosePipelineState(data, data.mtlpipelineprims, renderer->blendMode)];

[data.mtlcmdencoder setFragmentBytes:color length:sizeof(color) atIndex:0];

float *ptr = verts;

for (int i = 0; i < count; i++, points++) {

*ptr = adjustx(points->x); ptr++;

*ptr = adjusty(points->y); ptr++;

}

[data.mtlcmdencoder setVertexBytes:verts length:vertlen atIndex:0];

[data.mtlcmdencoder drawPrimitives:primtype vertexStart:0 vertexCount:count];

SDL_free(verts);

return 0;

}}

static int

METAL_RenderDrawPoints(SDL_Renderer * renderer, const SDL_FPoint * points, int count)

{

return DrawVerts(renderer, points, count, MTLPrimitiveTypePoint);

}

static int

METAL_RenderDrawLines(SDL_Renderer * renderer, const SDL_FPoint * points, int count)

{

return DrawVerts(renderer, points, count, MTLPrimitiveTypeLineStrip);

}

static int

METAL_RenderFillRects(SDL_Renderer * renderer, const SDL_FRect * rects, int count)

{ @autoreleasepool {

METAL_ActivateRenderer(renderer);

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

// !!! FIXME: render color should live in a dedicated uniform buffer.

const float color[4] = { ((float)renderer->r) / 255.0f, ((float)renderer->g) / 255.0f, ((float)renderer->b) / 255.0f, ((float)renderer->a) / 255.0f };

[data.mtlcmdencoder setRenderPipelineState:ChoosePipelineState(data, data.mtlpipelineprims, renderer->blendMode)];

[data.mtlcmdencoder setFragmentBytes:color length:sizeof(color) atIndex:0];

for (int i = 0; i < count; i++, rects++) {

if ((rects->w <= 0.0f) || (rects->h <= 0.0f)) continue;

const float verts[] = {

adjustx(rects->x), adjusty(rects->y + rects->h),

adjustx(rects->x), adjusty(rects->y),

adjustx(rects->x + rects->w), adjusty(rects->y + rects->h),

adjustx(rects->x + rects->w), adjusty(rects->y)

};

[data.mtlcmdencoder setVertexBytes:verts length:sizeof(verts) atIndex:0];

[data.mtlcmdencoder drawPrimitives:MTLPrimitiveTypeTriangleStrip vertexStart:0 vertexCount:4];

}

return 0;

}}

static int

METAL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * srcrect, const SDL_FRect * dstrect)

{ @autoreleasepool {

METAL_ActivateRenderer(renderer);

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

METAL_TextureData *texturedata = (__bridge METAL_TextureData *)texture->driverdata;

const float texw = (float) texturedata.mtltexture.width;

const float texh = (float) texturedata.mtltexture.height;

const float xy[] = {

adjustx(dstrect->x), adjusty(dstrect->y + dstrect->h),

adjustx(dstrect->x), adjusty(dstrect->y),

adjustx(dstrect->x + dstrect->w), adjusty(dstrect->y + dstrect->h),

adjustx(dstrect->x + dstrect->w), adjusty(dstrect->y)

};

const float uv[] = {

normtex(srcrect->x, texw), normtex(srcrect->y + srcrect->h, texh),

normtex(srcrect->x, texw), normtex(srcrect->y, texh),

normtex(srcrect->x + srcrect->w, texw), normtex(srcrect->y + srcrect->h, texh),

normtex(srcrect->x + srcrect->w, texw), normtex(srcrect->y, texh)

};

float color[4] = { 1.0f, 1.0f, 1.0f, 1.0f };

if (texture->modMode) {

color[0] = ((float)texture->r) / 255.0f;

color[1] = ((float)texture->g) / 255.0f;

color[2] = ((float)texture->b) / 255.0f;

color[3] = ((float)texture->a) / 255.0f;

}

[data.mtlcmdencoder setRenderPipelineState:ChoosePipelineState(data, data.mtlpipelinecopy, texture->blendMode)];

[data.mtlcmdencoder setVertexBytes:xy length:sizeof(xy) atIndex:0];

[data.mtlcmdencoder setVertexBytes:uv length:sizeof(uv) atIndex:1];

[data.mtlcmdencoder setVertexBuffer:data.mtlbufidentitytransform offset:0 atIndex:3];

[data.mtlcmdencoder setFragmentBytes:color length:sizeof(color) atIndex:0];

[data.mtlcmdencoder setFragmentTexture:texturedata.mtltexture atIndex:0];

[data.mtlcmdencoder setFragmentSamplerState:texturedata.mtlsampler atIndex:0];

[data.mtlcmdencoder drawPrimitives:MTLPrimitiveTypeTriangleStrip vertexStart:0 vertexCount:4];

return 0;

}}

static int

METAL_RenderCopyEx(SDL_Renderer * renderer, SDL_Texture * texture,

const SDL_Rect * srcrect, const SDL_FRect * dstrect,

const double angle, const SDL_FPoint *center, const SDL_RendererFlip flip)

{ @autoreleasepool {

METAL_ActivateRenderer(renderer);

METAL_RenderData *data = (__bridge METAL_RenderData *) renderer->driverdata;

METAL_TextureData *texturedata = (__bridge METAL_TextureData *)texture->driverdata;

const float texw = (float) texturedata.mtltexture.width;

const float texh = (float) texturedata.mtltexture.height;

float transform[16];

float minu, maxu, minv, maxv;

minu = normtex(srcrect->x, texw);

maxu = normtex(srcrect->x + srcrect->w, texw);

minv = normtex(srcrect->y, texh);

maxv = normtex(srcrect->y + srcrect->h, texh);

if (flip & SDL_FLIP_HORIZONTAL) {

float tmp = maxu;

maxu = minu;

minu = tmp;

}

if (flip & SDL_FLIP_VERTICAL) {

float tmp = maxv;

maxv = minv;

minv = tmp;

}

const float uv[] = {

minu, maxv,

minu, minv,

maxu, maxv,

maxu, minv

};

const float xy[] = {

adjustx(-center->x), adjusty(dstrect->h - center->y),

adjustx(-center->x), adjusty(-center->y),

adjustx(dstrect->w - center->x), adjusty(dstrect->h - center->y),

adjustx(dstrect->w - center->x), adjusty(-center->y)

};

{

float rads = (float)(M_PI * (float) angle / 180.0f);

float c = cosf(rads), s = sinf(rads);

SDL_memset(transform, 0, sizeof(transform));