Add renderer blend state contract

src/renderer_api/renderer_api.cpp

@@ -131,6 +131,63 @@ pp::foundation::Status validate_viewport(Viewport viewport, Extent2D target_exte
     return pp::foundation::Status::success();
 }
 
+pp::foundation::Status validate_blend_factor(BlendFactor factor) noexcept
+{
+    switch (factor) {
+    case BlendFactor::zero:
+    case BlendFactor::one:
+    case BlendFactor::source_alpha:
+    case BlendFactor::one_minus_source_alpha:
+    case BlendFactor::destination_alpha:
+    case BlendFactor::one_minus_destination_alpha:
+        return pp::foundation::Status::success();
+    }
+
+    return pp::foundation::Status::invalid_argument("blend factor is not supported");
+}
+
+pp::foundation::Status validate_blend_op(BlendOp op) noexcept
+{
+    switch (op) {
+    case BlendOp::add:
+    case BlendOp::subtract:
+    case BlendOp::reverse_subtract:
+        return pp::foundation::Status::success();
+    }
+
+    return pp::foundation::Status::invalid_argument("blend operation is not supported");
+}
+
+pp::foundation::Status validate_blend_state(BlendState state) noexcept
+{
+    const auto source_color = validate_blend_factor(state.source_color);
+    if (!source_color.ok()) {
+        return source_color;
+    }
+
+    const auto destination_color = validate_blend_factor(state.destination_color);
+    if (!destination_color.ok()) {
+        return destination_color;
+    }
+
+    const auto color_op = validate_blend_op(state.color_op);
+    if (!color_op.ok()) {
+        return color_op;
+    }
+
+    const auto source_alpha = validate_blend_factor(state.source_alpha);
+    if (!source_alpha.ok()) {
+        return source_alpha;
+    }
+
+    const auto destination_alpha = validate_blend_factor(state.destination_alpha);
+    if (!destination_alpha.ok()) {
+        return destination_alpha;
+    }
+
+    return validate_blend_op(state.alpha_op);
+}
+
 pp::foundation::Status validate_mesh_desc(MeshDesc desc) noexcept
 {
     if (desc.vertex_count == 0) {
@@ -324,4 +381,38 @@ const char* blit_filter_name(BlitFilter filter) noexcept
     return "unknown";
 }
 
+const char* blend_factor_name(BlendFactor factor) noexcept
+{
+    switch (factor) {
+    case BlendFactor::zero:
+        return "zero";
+    case BlendFactor::one:
+        return "one";
+    case BlendFactor::source_alpha:
+        return "source_alpha";
+    case BlendFactor::one_minus_source_alpha:
+        return "one_minus_source_alpha";
+    case BlendFactor::destination_alpha:
+        return "destination_alpha";
+    case BlendFactor::one_minus_destination_alpha:
+        return "one_minus_destination_alpha";
+    }
+
+    return "unknown";
+}
+
+const char* blend_op_name(BlendOp op) noexcept
+{
+    switch (op) {
+    case BlendOp::add:
+        return "add";
+    case BlendOp::subtract:
+        return "subtract";
+    case BlendOp::reverse_subtract:
+        return "reverse_subtract";
+    }
+
+    return "unknown";
+}
+
 }