1 files changed, 299 insertions, 0 deletions

diff --git a/contrib/SDL-3.2.8/src/render/metal/SDL_shaders_metal.metal b/contrib/SDL-3.2.8/src/render/metal/SDL_shaders_metal.metal
new file mode 100644
index 0000000..c266670
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/render/metal/SDL_shaders_metal.metal
@@ -0,0 +1,299 @@
+#include <metal_common>
+#include <metal_texture>
+#include <metal_matrix>
+
+using namespace metal;
+
+// These should mirror the definitions in SDL_render_metal.m
+#define TONEMAP_NONE            0
+#define TONEMAP_LINEAR          1
+#define TONEMAP_CHROME          2
+
+#define TEXTURETYPE_NONE        0
+#define TEXTURETYPE_RGB         1
+#define TEXTURETYPE_NV12        2
+#define TEXTURETYPE_NV21        3
+#define TEXTURETYPE_YUV         4
+
+#define INPUTTYPE_UNSPECIFIED   0
+#define INPUTTYPE_SRGB          1
+#define INPUTTYPE_SCRGB         2
+#define INPUTTYPE_HDR10         3
+
+struct ShaderConstants
+{
+    float scRGB_output;
+    float texture_type;
+    float input_type;
+    float color_scale;
+
+    float tonemap_method;
+    float tonemap_factor1;
+    float tonemap_factor2;
+    float sdr_white_point;
+};
+
+struct YUVDecode
+{
+    float3 offset;
+    float3x3 matrix;
+};
+
+float sRGBtoLinear(float v)
+{
+    if (v <= 0.04045) {
+        v = (v / 12.92);
+    } else {
+        v = pow(abs(v + 0.055) / 1.055, 2.4);
+    }
+    return v;
+}
+
+float sRGBfromLinear(float v)
+{
+    if (v <= 0.0031308) {
+        v = (v * 12.92);
+    } else {
+        v = (pow(abs(v), 1.0 / 2.4) * 1.055 - 0.055);
+    }
+    return v;
+}
+
+float3 PQtoLinear(float3 v, float sdr_white_point)
+{
+    const float c1 = 0.8359375;
+    const float c2 = 18.8515625;
+    const float c3 = 18.6875;
+    const float oo_m1 = 1.0 / 0.1593017578125;
+    const float oo_m2 = 1.0 / 78.84375;
+
+    float3 num = max(pow(abs(v), oo_m2) - c1, 0.0);
+    float3 den = c2 - c3 * pow(abs(v), oo_m2);
+    return (10000.0 * pow(abs(num / den), oo_m1) / sdr_white_point);
+}
+
+float3 ApplyTonemap(float3 v, float input_type, float tonemap_method, float tonemap_factor1, float tonemap_factor2)
+{
+    const float3x3 mat709to2020 = {
+        { 0.627404, 0.329283, 0.043313 },
+        { 0.069097, 0.919541, 0.011362 },
+        { 0.016391, 0.088013, 0.895595 }
+    };
+    const float3x3 mat2020to709 = {
+        { 1.660496, -0.587656, -0.072840 },
+        { -0.124547, 1.132895, -0.008348 },
+        { -0.018154, -0.100597, 1.118751 }
+    };
+
+    if (tonemap_method == TONEMAP_LINEAR) {
+        v *= tonemap_factor1;
+    } else if (tonemap_method == TONEMAP_CHROME) {
+        if (input_type == INPUTTYPE_SCRGB) {
+            // Convert to BT.2020 colorspace for tone mapping
+            v = v * mat709to2020;
+        }
+
+        float vmax = max(v.r, max(v.g, v.b));
+        if (vmax > 0.0) {
+            float scale = (1.0 + tonemap_factor1 * vmax) / (1.0 + tonemap_factor2 * vmax);
+            v *= scale;
+        }
+
+        if (input_type == INPUTTYPE_SCRGB) {
+            // Convert to BT.709 colorspace after tone mapping
+            v = v * mat2020to709;
+        }
+    }
+    return v;
+}
+
+float4 GetOutputColorSimple(float4 rgba, float color_scale)
+{
+    float4 output;
+
+    output.rgb = rgba.rgb * color_scale;
+    output.a = rgba.a;
+
+    return output;
+}
+
+float3 GetOutputColorFromSRGB(float3 rgb, float scRGB_output, float color_scale)
+{
+    float3 output;
+
+    if (scRGB_output) {
+        rgb.r = sRGBtoLinear(rgb.r);
+        rgb.g = sRGBtoLinear(rgb.g);
+        rgb.b = sRGBtoLinear(rgb.b);
+    }
+
+    output = rgb * color_scale;
+
+    return output;
+}
+
+float3 GetOutputColorFromLinear(float3 rgb, float scRGB_output, float color_scale)
+{
+    float3 output;
+
+    output = rgb * color_scale;
+
+    if (!scRGB_output) {
+        output.r = sRGBfromLinear(output.r);
+        output.g = sRGBfromLinear(output.g);
+        output.b = sRGBfromLinear(output.b);
+        output = clamp(output, 0.0, 1.0);
+    }
+
+    return output;
+}
+
+float4 GetOutputColor(float4 rgba, constant ShaderConstants &c)
+{
+    const float3x3 mat2020to709 = {
+        { 1.660496, -0.587656, -0.072840 },
+        { -0.124547, 1.132895, -0.008348 },
+        { -0.018154, -0.100597, 1.118751 }
+    };
+    float4 output;
+
+    if (c.input_type == INPUTTYPE_HDR10) {
+        rgba.rgb = PQtoLinear(rgba.rgb, c.sdr_white_point);
+    }
+
+    if (c.tonemap_method != TONEMAP_NONE) {
+        rgba.rgb = ApplyTonemap(rgba.rgb, c.input_type, c.tonemap_method, c.tonemap_factor1, c.tonemap_factor2);
+    }
+
+    if (c.input_type == INPUTTYPE_SRGB) {
+        if (c.texture_type == TEXTURETYPE_RGB) {
+            // The sampler has already converted to linear if necessary
+            output.rgb = rgba.rgb * c.color_scale;
+        } else {
+            output.rgb = GetOutputColorFromSRGB(rgba.rgb, c.scRGB_output, c.color_scale);
+        }
+    } else if (c.input_type == INPUTTYPE_SCRGB) {
+        output.rgb = GetOutputColorFromLinear(rgba.rgb, c.scRGB_output, c.color_scale);
+    } else if (c.input_type == INPUTTYPE_HDR10) {
+        rgba.rgb = rgba.rgb * mat2020to709;
+        output.rgb = GetOutputColorFromLinear(rgba.rgb, c.scRGB_output, c.color_scale);
+    } else {
+        // Unexpected input type, use magenta error color
+        output.rgb = float3(1.0, 0.0, 1.0);
+    }
+    output.a = rgba.a;
+
+    return output;
+}
+
+struct SolidVertexInput
+{
+    float2 position [[attribute(0)]];
+    float4 color    [[attribute(1)]];
+};
+
+struct SolidVertexOutput
+{
+    float4 position [[position]];
+    float4 color;
+    float pointSize [[point_size]];
+};
+
+vertex SolidVertexOutput SDL_Solid_vertex(SolidVertexInput in [[stage_in]],
+                                          constant float4x4 &projection [[buffer(2)]],
+                                          constant float4x4 &transform [[buffer(3)]])
+{
+    SolidVertexOutput v;
+    v.position = (projection * transform) * float4(in.position, 0.0f, 1.0f);
+    v.color = in.color;
+    v.pointSize = 1.0f;
+    return v;
+}
+
+fragment float4 SDL_Solid_fragment(SolidVertexInput in [[stage_in]],
+                                   constant ShaderConstants &c [[buffer(0)]])
+{
+    return GetOutputColorSimple(1.0, c.color_scale) * in.color;
+}
+
+struct CopyVertexInput
+{
+    float2 position [[attribute(0)]];
+    float4 color    [[attribute(1)]];
+    float2 texcoord [[attribute(2)]];
+};
+
+struct CopyVertexOutput
+{
+    float4 position [[position]];
+    float4 color;
+    float2 texcoord;
+};
+
+vertex CopyVertexOutput SDL_Copy_vertex(CopyVertexInput in [[stage_in]],
+                                        constant float4x4 &projection [[buffer(2)]],
+                                        constant float4x4 &transform [[buffer(3)]])
+{
+    CopyVertexOutput v;
+    v.position = (projection * transform) * float4(in.position, 0.0f, 1.0f);
+    v.color = in.color;
+    v.texcoord = in.texcoord;
+    return v;
+}
+
+fragment float4 SDL_Copy_fragment(CopyVertexOutput vert [[stage_in]],
+                                  constant ShaderConstants &c [[buffer(0)]],
+                                  texture2d<float> tex [[texture(0)]],
+                                  sampler s [[sampler(0)]])
+{
+    float4 rgba = tex.sample(s, vert.texcoord);
+    return GetOutputColor(rgba, c) * vert.color;
+}
+
+fragment float4 SDL_YUV_fragment(CopyVertexOutput vert [[stage_in]],
+                                 constant ShaderConstants &c [[buffer(0)]],
+                                 constant YUVDecode &decode [[buffer(1)]],
+                                 texture2d<float> texY [[texture(0)]],
+                                 texture2d_array<float> texUV [[texture(1)]],
+                                 sampler s [[sampler(0)]])
+{
+    float3 yuv;
+    yuv.x = texY.sample(s, vert.texcoord).r;
+    yuv.y = texUV.sample(s, vert.texcoord, 0).r;
+    yuv.z = texUV.sample(s, vert.texcoord, 1).r;
+
+    float4 rgba;
+    rgba.rgb = (yuv + decode.offset) * decode.matrix;
+    rgba.a = 1.0;
+
+    return GetOutputColor(rgba, c) * vert.color;
+}
+
+fragment float4 SDL_NV12_fragment(CopyVertexOutput vert [[stage_in]],
+                                  constant ShaderConstants &c [[buffer(0)]],
+                                  constant YUVDecode &decode [[buffer(1)]],
+                                  texture2d<float> texY [[texture(0)]],
+                                  texture2d<float> texUV [[texture(1)]],
+                                  sampler s [[sampler(0)]])
+{
+    float4 rgba;
+    if (c.texture_type == TEXTURETYPE_NV12) {
+        float3 yuv;
+        yuv.x = texY.sample(s, vert.texcoord).r;
+        yuv.yz = texUV.sample(s, vert.texcoord).rg;
+
+        rgba.rgb = (yuv + decode.offset) * decode.matrix;
+    } else if (c.texture_type == TEXTURETYPE_NV21) {
+        float3 yuv;
+        yuv.x = texY.sample(s, vert.texcoord).r;
+        yuv.yz = texUV.sample(s, vert.texcoord).gr;
+
+        rgba.rgb = (yuv + decode.offset) * decode.matrix;
+    } else {
+        // Unexpected texture type, use magenta error color
+        rgba.rgb = float3(1.0, 0.0, 1.0);
+    }
+    rgba.a = 1.0;
+
+    return GetOutputColor(rgba, c) * vert.color;
+}