Expand renderer API interfaces

src/renderer_api/renderer_api.cpp

@@ -1,5 +1,6 @@
 #include "renderer_api/renderer_api.h"
 
+#include <cmath>
 #include <limits>
 
 namespace pp::renderer {
@@ -66,6 +67,62 @@ pp::foundation::Result<std::uint64_t> texture_byte_size(TextureDesc desc) noexce
     return pp::foundation::Result<std::uint64_t>::success(bytes);
 }
 
+pp::foundation::Status validate_viewport(Viewport viewport, Extent2D target_extent) noexcept
+{
+    const auto extent_status = validate_extent(target_extent);
+    if (!extent_status.ok()) {
+        return extent_status;
+    }
+
+    if (viewport.x < 0 || viewport.y < 0) {
+        return pp::foundation::Status::invalid_argument("viewport origin must be non-negative");
+    }
+
+    if (viewport.width == 0 || viewport.height == 0) {
+        return pp::foundation::Status::invalid_argument("viewport size must be greater than zero");
+    }
+
+    if (!std::isfinite(viewport.min_depth) || !std::isfinite(viewport.max_depth)) {
+        return pp::foundation::Status::invalid_argument("viewport depth range must be finite");
+    }
+
+    if (viewport.min_depth < 0.0F || viewport.max_depth > 1.0F || viewport.min_depth > viewport.max_depth) {
+        return pp::foundation::Status::out_of_range("viewport depth range must be within 0..1 and ordered");
+    }
+
+    const auto x = static_cast<std::uint32_t>(viewport.x);
+    const auto y = static_cast<std::uint32_t>(viewport.y);
+    if (x > target_extent.width || y > target_extent.height) {
+        return pp::foundation::Status::out_of_range("viewport origin is outside the render target");
+    }
+
+    if (viewport.width > target_extent.width - x || viewport.height > target_extent.height - y) {
+        return pp::foundation::Status::out_of_range("viewport exceeds render target bounds");
+    }
+
+    return pp::foundation::Status::success();
+}
+
+pp::foundation::Status validate_mesh_desc(MeshDesc desc) noexcept
+{
+    if (desc.vertex_count == 0) {
+        return pp::foundation::Status::invalid_argument("mesh must contain at least one vertex");
+    }
+
+    if (desc.vertex_count > max_mesh_vertices || desc.index_count > max_mesh_vertices) {
+        return pp::foundation::Status::out_of_range("mesh vertex or index count exceeds the configured limit");
+    }
+
+    switch (desc.topology) {
+    case PrimitiveTopology::triangles:
+    case PrimitiveTopology::triangle_strip:
+    case PrimitiveTopology::lines:
+        return pp::foundation::Status::success();
+    }
+
+    return pp::foundation::Status::invalid_argument("mesh topology is not supported");
+}
+
 pp::foundation::Status validate_readback_region(TextureDesc desc, ReadbackRegion region) noexcept
 {
     const auto extent_status = validate_extent(desc.extent);
@@ -102,4 +159,18 @@ const char* texture_format_name(TextureFormat format) noexcept
     return "unknown";
 }
 
+const char* primitive_topology_name(PrimitiveTopology topology) noexcept
+{
+    switch (topology) {
+    case PrimitiveTopology::triangles:
+        return "triangles";
+    case PrimitiveTopology::triangle_strip:
+        return "triangle_strip";
+    case PrimitiveTopology::lines:
+        return "lines";
+    }
+
+    return "unknown";
+}
+
 }

src/renderer_api/renderer_api.h

@@ -2,11 +2,13 @@
 
 #include "foundation/result.h"
 
+#include <cstddef>
 #include <cstdint>
 
 namespace pp::renderer {
 
 constexpr std::uint32_t max_texture_dimension = 32768;
+constexpr std::uint32_t max_mesh_vertices = 16777216;
 constexpr std::uint64_t max_texture_bytes = 1024ULL * 1024ULL * 1024ULL;
 
 enum class TextureFormat : std::uint8_t {
@@ -33,12 +35,70 @@ struct ReadbackRegion {
     std::uint32_t height = 0;
 };
 
+struct Viewport {
+    std::int32_t x = 0;
+    std::int32_t y = 0;
+    std::uint32_t width = 0;
+    std::uint32_t height = 0;
+    float min_depth = 0.0F;
+    float max_depth = 1.0F;
+};
+
+struct ClearColor {
+    float r = 0.0F;
+    float g = 0.0F;
+    float b = 0.0F;
+    float a = 0.0F;
+};
+
+enum class PrimitiveTopology : std::uint8_t {
+    triangles,
+    triangle_strip,
+    lines,
+};
+
+struct MeshDesc {
+    std::uint32_t vertex_count = 0;
+    std::uint32_t index_count = 0;
+    PrimitiveTopology topology = PrimitiveTopology::triangles;
+};
+
+struct ShaderStageSource {
+    const char* entry_point = "main";
+    const char* source = nullptr;
+    std::size_t source_size = 0;
+};
+
+struct ShaderProgramDesc {
+    const char* debug_name = "";
+    ShaderStageSource vertex;
+    ShaderStageSource fragment;
+};
+
 class ITexture2D {
 public:
     virtual ~ITexture2D() = default;
     [[nodiscard]] virtual TextureDesc desc() const noexcept = 0;
 };
 
+class IRenderTarget {
+public:
+    virtual ~IRenderTarget() = default;
+    [[nodiscard]] virtual TextureDesc color_desc() const noexcept = 0;
+};
+
+class IShaderProgram {
+public:
+    virtual ~IShaderProgram() = default;
+    [[nodiscard]] virtual const char* debug_name() const noexcept = 0;
+};
+
+class IMesh {
+public:
+    virtual ~IMesh() = default;
+    [[nodiscard]] virtual MeshDesc desc() const noexcept = 0;
+};
+
 class IReadbackBuffer {
 public:
     virtual ~IReadbackBuffer() = default;
@@ -51,10 +111,34 @@ public:
     virtual void marker(const char* component, const char* name) noexcept = 0;
 };
 
+class ICommandContext {
+public:
+    virtual ~ICommandContext() = default;
+    [[nodiscard]] virtual pp::foundation::Status begin_render_pass(
+        IRenderTarget& target,
+        ClearColor clear_color) noexcept = 0;
+    [[nodiscard]] virtual pp::foundation::Status set_viewport(Viewport viewport) noexcept = 0;
+    [[nodiscard]] virtual pp::foundation::Status bind_shader(IShaderProgram& shader) noexcept = 0;
+    [[nodiscard]] virtual pp::foundation::Status bind_mesh(IMesh& mesh) noexcept = 0;
+    [[nodiscard]] virtual pp::foundation::Status draw() noexcept = 0;
+    virtual void end_render_pass() noexcept = 0;
+};
+
+class IRenderDevice {
+public:
+    virtual ~IRenderDevice() = default;
+    [[nodiscard]] virtual const char* backend_name() const noexcept = 0;
+    [[nodiscard]] virtual ICommandContext& immediate_context() noexcept = 0;
+    [[nodiscard]] virtual IRenderTrace* trace() noexcept = 0;
+};
+
 [[nodiscard]] std::uint32_t bytes_per_pixel(TextureFormat format) noexcept;
 [[nodiscard]] pp::foundation::Status validate_extent(Extent2D extent) noexcept;
+[[nodiscard]] pp::foundation::Status validate_viewport(Viewport viewport, Extent2D target_extent) noexcept;
+[[nodiscard]] pp::foundation::Status validate_mesh_desc(MeshDesc desc) noexcept;
 [[nodiscard]] pp::foundation::Result<std::uint64_t> texture_byte_size(TextureDesc desc) noexcept;
 [[nodiscard]] pp::foundation::Status validate_readback_region(TextureDesc desc, ReadbackRegion region) noexcept;
 [[nodiscard]] const char* texture_format_name(TextureFormat format) noexcept;
+[[nodiscard]] const char* primitive_topology_name(PrimitiveTopology topology) noexcept;
 
 }