LibSoftGPU: Remove OpenGL type for alpha blend factors

Replaces the GLenum used for configuring alpha blend factors in the
SoftGPU device with out own enum.

Userland/Libraries/LibGL/SoftwareGLContext.cpp

@@ -1130,9 +1130,39 @@ void SoftwareGLContext::gl_blend_func(GLenum src_factor, GLenum dst_factor)
     m_blend_source_factor = src_factor;
     m_blend_destination_factor = dst_factor;
 
+    auto map_gl_blend_factor_to_device = [](GLenum factor) constexpr
+    {
+        switch (factor) {
+        case GL_ZERO:
+            return SoftGPU::BlendFactor::Zero;
+        case GL_ONE:
+            return SoftGPU::BlendFactor::One;
+        case GL_SRC_ALPHA:
+            return SoftGPU::BlendFactor::SrcAlpha;
+        case GL_ONE_MINUS_SRC_ALPHA:
+            return SoftGPU::BlendFactor::OneMinusSrcAlpha;
+        case GL_SRC_COLOR:
+            return SoftGPU::BlendFactor::SrcColor;
+        case GL_ONE_MINUS_SRC_COLOR:
+            return SoftGPU::BlendFactor::OneMinusSrcColor;
+        case GL_DST_ALPHA:
+            return SoftGPU::BlendFactor::DstAlpha;
+        case GL_ONE_MINUS_DST_ALPHA:
+            return SoftGPU::BlendFactor::OneMinusDstAlpha;
+        case GL_DST_COLOR:
+            return SoftGPU::BlendFactor::DstColor;
+        case GL_ONE_MINUS_DST_COLOR:
+            return SoftGPU::BlendFactor::OneMinusDstColor;
+        case GL_SRC_ALPHA_SATURATE:
+            return SoftGPU::BlendFactor::SrcAlphaSaturate;
+        default:
+            VERIFY_NOT_REACHED();
+        }
+    };
+
     auto options = m_rasterizer.options();
-    options.blend_source_factor = m_blend_source_factor;
+    options.blend_source_factor = map_gl_blend_factor_to_device(m_blend_source_factor);
-    options.blend_destination_factor = m_blend_destination_factor;
+    options.blend_destination_factor = map_gl_blend_factor_to_device(m_blend_destination_factor);
     m_rasterizer.set_options(options);
 }
 

Userland/Libraries/LibSoftGPU/Device.cpp

@@ -60,7 +60,7 @@ static Gfx::IntRect scissor_box_to_window_coordinates(Gfx::IntRect const& scisso
     return scissor_box.translated(0, window_rect.height() - 2 * scissor_box.y() - scissor_box.height());
 }
 
-static constexpr void setup_blend_factors(GLenum mode, FloatVector4& constant, float& src_alpha, float& dst_alpha, float& src_color, float& dst_color)
+static constexpr void setup_blend_factors(BlendFactor mode, FloatVector4& constant, float& src_alpha, float& dst_alpha, float& src_color, float& dst_color)
 {
     constant = { 0.0f, 0.0f, 0.0f, 0.0f };
     src_alpha = 0;
@@ -69,40 +69,40 @@ static constexpr void setup_blend_factors(GLenum mode, FloatVector4& constant, f
     dst_color = 0;
 
     switch (mode) {
-    case GL_ZERO:
+    case BlendFactor::Zero:
         break;
-    case GL_ONE:
+    case BlendFactor::One:
         constant = { 1.0f, 1.0f, 1.0f, 1.0f };
         break;
-    case GL_SRC_COLOR:
+    case BlendFactor::SrcColor:
         src_color = 1;
         break;
-    case GL_ONE_MINUS_SRC_COLOR:
+    case BlendFactor::OneMinusSrcColor:
         constant = { 1.0f, 1.0f, 1.0f, 1.0f };
         src_color = -1;
         break;
-    case GL_SRC_ALPHA:
+    case BlendFactor::SrcAlpha:
         src_alpha = 1;
         break;
-    case GL_ONE_MINUS_SRC_ALPHA:
+    case BlendFactor::OneMinusSrcAlpha:
         constant = { 1.0f, 1.0f, 1.0f, 1.0f };
         src_alpha = -1;
         break;
-    case GL_DST_ALPHA:
+    case BlendFactor::DstAlpha:
         dst_alpha = 1;
         break;
-    case GL_ONE_MINUS_DST_ALPHA:
+    case BlendFactor::OneMinusDstAlpha:
         constant = { 1.0f, 1.0f, 1.0f, 1.0f };
         dst_alpha = -1;
         break;
-    case GL_DST_COLOR:
+    case BlendFactor::DstColor:
         dst_color = 1;
         break;
-    case GL_ONE_MINUS_DST_COLOR:
+    case BlendFactor::OneMinusDstColor:
         constant = { 1.0f, 1.0f, 1.0f, 1.0f };
         dst_color = -1;
         break;
-    case GL_SRC_ALPHA_SATURATE:
+    case BlendFactor::SrcAlphaSaturate:
         // FIXME: How do we implement this?
         break;
     default:

Userland/Libraries/LibSoftGPU/Device.h

@@ -37,6 +37,20 @@ enum class AlphaTestFunction {
     Greater,
 };
 
+enum class BlendFactor {
+    Zero,
+    One,
+    SrcAlpha,
+    OneMinusSrcAlpha,
+    SrcColor,
+    OneMinusSrcColor,
+    DstAlpha,
+    OneMinusDstAlpha,
+    DstColor,
+    OneMinusDstColor,
+    SrcAlphaSaturate,
+};
+
 struct RasterizerOptions {
     bool shade_smooth { true };
     bool enable_depth_test { false };
@@ -45,8 +59,8 @@ struct RasterizerOptions {
     AlphaTestFunction alpha_test_func { AlphaTestFunction::Always };
     float alpha_test_ref_value { 0 };
     bool enable_blending { false };
-    GLenum blend_source_factor { GL_ONE };
+    BlendFactor blend_source_factor { BlendFactor::One };
-    GLenum blend_destination_factor { GL_ONE };
+    BlendFactor blend_destination_factor { BlendFactor::One };
     u32 color_mask { 0xffffffff };
     float depth_min { 0 };
     float depth_max { 1 };