Working on adding vulkan renderer

.gitignore

@@ -4,4 +4,5 @@ cmake-build-release/
 .idea/
 node_modules/
 *.dSYM
-.vs/
+.vs/
+out/

renderers/vulkan/clay_renderer_vulkan.c

@@ -0,0 +1,287 @@
+// Clay Vulkan renderer sample (C17/C20 friendly)
+// This file demonstrates how to traverse Clay_RenderCommandArray and submit Vulkan draw calls.
+// The implementation favors clarity over micro-optimizations and documents future improvements.
+// Vulkan reference: https://vulkan.lunarg.com/doc/sdk
+// ImGui integration notes (for font atlas usage ideas): https://github.com/ocornut/imgui/wiki
+
+#include <stdint.h>
+#include <string.h>
+#include <vulkan/vulkan.h>
+#include "clay.h"
+
+// Forward declarations -------------------------------------------------------
+struct ClayVulkanRenderer;
+static void ClayVulkan_PushScissor(struct ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer);
+static void ClayVulkan_PopScissor(struct ClayVulkanRenderer* renderer, VkCommandBuffer commandBuffer);
+static void ClayVulkan_DrawRectangle(struct ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer);
+static void ClayVulkan_DrawBorder(struct ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer);
+static void ClayVulkan_DrawImage(struct ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer);
+static void ClayVulkan_DrawText(struct ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer);
+static void ClayVulkan_DrawCustom(struct ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer);
+
+// Resource cache keyed by Clay IDs ------------------------------------------
+typedef struct ClayVulkanTexture
+{
+    uint32_t m_Id;          // Clay image id
+    VkImageView m_ImageView;
+    VkSampler m_Sampler;
+    VkDescriptorSet m_DescriptorSet;
+} ClayVulkanTexture;
+
+typedef struct ClayVulkanFont
+{
+    uint16_t m_FontId;
+    uint16_t m_FontSize;
+    void* m_FontUserData;   // Pointer to glyph atlas / font metrics owned by the application
+} ClayVulkanFont;
+
+typedef struct ClayVulkanResourceCache
+{
+    ClayVulkanTexture m_Textures[64];
+    uint32_t m_TextureCount;
+    ClayVulkanFont m_Fonts[32];
+    uint32_t m_FontCount;
+} ClayVulkanResourceCache;
+
+// Renderer state ------------------------------------------------------------
+typedef struct ClayVulkanRenderer
+{
+    VkDevice m_Device;
+    VkRenderPass m_RenderPass; // Compatible with the framebuffer bound by the host application
+    VkPipeline m_RectPipeline;
+    VkPipeline m_TextPipeline;
+    VkPipeline m_ImagePipeline;
+    VkPipelineLayout m_PipelineLayout;
+    VkCommandBuffer m_ActiveCommandBuffer;
+    VkRect2D m_ScissorStack[16];
+    uint32_t m_ScissorCount;
+    ClayVulkanResourceCache m_ResourceCache;
+    // The sample keeps descriptor pools outside; the host passes ready-to-bind descriptor sets.
+} ClayVulkanRenderer;
+
+// Utility: fetch or insert cached texture -----------------------------------
+static ClayVulkanTexture* ClayVulkan_GetTexture(ClayVulkanResourceCache* cache, uint32_t id)
+{
+    for (uint32_t it_Index = 0; it_Index < cache->m_TextureCount; ++it_Index)
+    {
+        ClayVulkanTexture* l_Texture = &cache->m_Textures[it_Index];
+        if (l_Texture->m_Id == id)
+        {
+            return l_Texture;
+        }
+    }
+    if (cache->m_TextureCount >= (uint32_t)(sizeof(cache->m_Textures) / sizeof(cache->m_Textures[0])))
+    {
+        return NULL; // Out of cache entries; caller can log and skip drawing.
+    }
+    ClayVulkanTexture* l_Texture = &cache->m_Textures[cache->m_TextureCount++];
+    memset(l_Texture, 0, sizeof(*l_Texture));
+    l_Texture->m_Id = id;
+
+    return l_Texture;
+}
+
+// Utility: fetch or insert cached font --------------------------------------
+static ClayVulkanFont* ClayVulkan_GetFont(ClayVulkanResourceCache* cache, uint16_t fontId, uint16_t fontSize)
+{
+    for (uint32_t it_Index = 0; it_Index < cache->m_FontCount; ++it_Index)
+    {
+        ClayVulkanFont* l_Font = &cache->m_Fonts[it_Index];
+        if (l_Font->m_FontId == fontId && l_Font->m_FontSize == fontSize)
+        {
+            return l_Font;
+        }
+    }
+    if (cache->m_FontCount >= (uint32_t)(sizeof(cache->m_Fonts) / sizeof(cache->m_Fonts[0])))
+    {
+        return NULL;
+    }
+    ClayVulkanFont* l_Font = &cache->m_Fonts[cache->m_FontCount++];
+    memset(l_Font, 0, sizeof(*l_Font));
+    l_Font->m_FontId = fontId;
+    l_Font->m_FontSize = fontSize;
+
+    return l_Font;
+}
+
+// Text measurement hook ------------------------------------------------------
+// Backs Clay_SetMeasureTextFunction and aligns with Clay_TextRenderData expectations.
+static Clay_Dimensions ClayVulkan_MeasureText(Clay_StringSlice text, Clay_TextElementConfig* config, void* userData)
+{
+    ClayVulkanRenderer* l_Renderer = (ClayVulkanRenderer*)userData;
+    ClayVulkanFont* l_Font = ClayVulkan_GetFont(&l_Renderer->m_ResourceCache, config->fontId, config->fontSize);
+    // The sample assumes the host supplies pixel metrics via m_FontUserData (e.g., stb_truetype bake results).
+    // For demonstration, approximate width using a monospaced assumption and letter spacing.
+    const float s_DefaultGlyphWidth = (float)config->fontSize * 0.6f;
+    float l_Width = (float)text.length * s_DefaultGlyphWidth + (float)config->letterSpacing * (float)text.length;
+    float l_Height = (float)config->lineHeight;
+    (void)l_Font; // In a real integration, sample glyph advances from l_Font->m_FontUserData.
+    
+    return (Clay_Dimensions) { l_Width, l_Height };
+}
+
+// Scissor management ---------------------------------------------------------
+static void ClayVulkan_PushScissor(ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer)
+{
+    if (renderer->m_ScissorCount >= (uint32_t)(sizeof(renderer->m_ScissorStack) / sizeof(renderer->m_ScissorStack[0])))
+    {
+        return; // Avoid overflow; future improvement could resize dynamically.
+    }
+    VkRect2D l_Rect = { 0 };
+    l_Rect.offset.x = (int32_t)command->boundingBox.x;
+    l_Rect.offset.y = (int32_t)command->boundingBox.y;
+    l_Rect.extent.width = (uint32_t)command->boundingBox.width;
+    l_Rect.extent.height = (uint32_t)command->boundingBox.height;
+    renderer->m_ScissorStack[renderer->m_ScissorCount++] = l_Rect;
+    vkCmdSetScissor(commandBuffer, 0, 1, &l_Rect);
+}
+
+static void ClayVulkan_PopScissor(ClayVulkanRenderer* renderer, VkCommandBuffer commandBuffer)
+{
+    if (renderer->m_ScissorCount == 0)
+    {
+        return;
+    }
+    renderer->m_ScissorCount--;
+    if (renderer->m_ScissorCount == 0)
+    {
+        // Fall back to a full viewport scissor. The host should have set a default scissor before calling render.
+        return;
+    }
+
+    VkRect2D l_Rect = renderer->m_ScissorStack[renderer->m_ScissorCount - 1];
+    vkCmdSetScissor(commandBuffer, 0, 1, &l_Rect);
+}
+
+// Rendering helpers ----------------------------------------------------------
+static void ClayVulkan_DrawRectangle(ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer)
+{
+    (void)renderer;
+    // The sample assumes a pipeline using push constants for color + corner radius and a unit quad vertex buffer.
+    vkCmdBindPipeline(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, renderer->m_RectPipeline);
+    // Future improvement: instance multiple rectangles in a single vkCmdDrawIndexed to amortize state changes.
+    vkCmdDraw(commandBuffer, 6, 1, 0, 0);
+}
+
+static void ClayVulkan_DrawBorder(ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer)
+{
+    (void)command;
+    // Border rendering could expand to 4 rectangles; here we rely on a shader that interprets width + corner radius from push constants.
+    vkCmdBindPipeline(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, renderer->m_RectPipeline);
+    vkCmdDraw(commandBuffer, 6, 1, 0, 0);
+}
+
+static void ClayVulkan_DrawImage(ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer)
+{
+    ClayVulkanTexture* l_Texture = ClayVulkan_GetTexture(&renderer->m_ResourceCache, command->id);
+    if (!l_Texture || !l_Texture->m_DescriptorSet) {
+        return; // Caller must populate descriptor sets before rendering.
+    }
+    vkCmdBindPipeline(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, renderer->m_ImagePipeline);
+    vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, renderer->m_PipelineLayout, 0, 1, &l_Texture->m_DescriptorSet, 0, NULL);
+    vkCmdDraw(commandBuffer, 6, 1, 0, 0);
+}
+
+static void ClayVulkan_DrawText(ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer)
+{
+    Clay_TextRenderData l_Text = command->renderData.text;
+    ClayVulkanFont* l_Font = ClayVulkan_GetFont(&renderer->m_ResourceCache, l_Text.fontId, l_Text.fontSize);
+    (void)l_Font;
+    // The host is expected to have built glyph vertices into a transient buffer before calling this renderer.
+    vkCmdBindPipeline(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, renderer->m_TextPipeline);
+    // Future improvement: bind per-font descriptor sets for font atlas textures instead of assuming a global one.
+    vkCmdDraw(commandBuffer, (uint32_t)l_Text.stringContents.length * 4, 1, 0, 0);
+}
+
+static void ClayVulkan_DrawCustom(ClayVulkanRenderer* renderer, const Clay_RenderCommand* command, VkCommandBuffer commandBuffer)
+{
+    (void)renderer;
+    (void)command;
+    // Custom elements give the host full control. Applications can use command->renderData.custom.customData to pick pipelines.
+    // Future improvement: provide callback hooks so applications can supply their own vkCmd* sequence here.
+    (void)commandBuffer;
+}
+
+// Main entry point -----------------------------------------------------------
+void Clay_Vulkan_Render(ClayVulkanRenderer* renderer, Clay_RenderCommandArray renderCommands, VkCommandBuffer commandBuffer)
+{
+    renderer->m_ActiveCommandBuffer = commandBuffer;
+    // Command traversal: the array is already z-sorted; we iterate sequentially and rely on lightweight state changes.
+    for (int32_t it_Command = 0; it_Command < renderCommands.length; ++it_Command)
+    {
+        Clay_RenderCommand* l_Command = Clay_RenderCommandArray_Get(&renderCommands, it_Command);
+        switch (l_Command->commandType)
+        {
+        case CLAY_RENDER_COMMAND_TYPE_RECTANGLE:
+            ClayVulkan_DrawRectangle(renderer, l_Command, commandBuffer);
+            break;
+        case CLAY_RENDER_COMMAND_TYPE_BORDER:
+            ClayVulkan_DrawBorder(renderer, l_Command, commandBuffer);
+            break;
+        case CLAY_RENDER_COMMAND_TYPE_TEXT:
+            ClayVulkan_DrawText(renderer, l_Command, commandBuffer);
+            break;
+        case CLAY_RENDER_COMMAND_TYPE_IMAGE:
+            ClayVulkan_DrawImage(renderer, l_Command, commandBuffer);
+            break;
+        case CLAY_RENDER_COMMAND_TYPE_SCISSOR_START:
+            ClayVulkan_PushScissor(renderer, l_Command, commandBuffer);
+            break;
+        case CLAY_RENDER_COMMAND_TYPE_SCISSOR_END:
+            ClayVulkan_PopScissor(renderer, commandBuffer);
+            break;
+        case CLAY_RENDER_COMMAND_TYPE_CUSTOM:
+            ClayVulkan_DrawCustom(renderer, l_Command, commandBuffer);
+            break;
+        default:
+            break;
+        }
+    }
+}
+
+// Initialization helpers ----------------------------------------------------
+void Clay_VulkanRenderer_Init(ClayVulkanRenderer* renderer, VkDevice device, VkRenderPass renderPass, VkPipelineLayout pipelineLayout)
+{
+    renderer->m_Device = device;
+    renderer->m_RenderPass = renderPass;
+    renderer->m_PipelineLayout = pipelineLayout;
+    renderer->m_RectPipeline = VK_NULL_HANDLE;
+    renderer->m_TextPipeline = VK_NULL_HANDLE;
+    renderer->m_ImagePipeline = VK_NULL_HANDLE;
+    renderer->m_ActiveCommandBuffer = VK_NULL_HANDLE;
+    renderer->m_ScissorCount = 0;
+
+    memset(&renderer->m_ResourceCache, 0, sizeof(renderer->m_ResourceCache));
+}
+
+void Clay_VulkanRenderer_SetPipelines(ClayVulkanRenderer* renderer, VkPipeline rectPipeline, VkPipeline textPipeline, VkPipeline imagePipeline)
+{
+    renderer->m_RectPipeline = rectPipeline;
+    renderer->m_TextPipeline = textPipeline;
+    renderer->m_ImagePipeline = imagePipeline;
+}
+
+// Hook into Clay's text measuring API.
+void Clay_VulkanRenderer_RegisterTextMeasure(ClayVulkanRenderer* renderer)
+{
+    Clay_SetMeasureTextFunction(ClayVulkan_MeasureText, renderer);
+}
+
+// Example for populating the texture cache with externally created descriptors.
+void Clay_VulkanRenderer_RegisterTexture(ClayVulkanRenderer* renderer, uint32_t clayId, VkImageView imageView, VkSampler sampler, VkDescriptorSet descriptorSet)
+{
+    ClayVulkanTexture* l_Texture = ClayVulkan_GetTexture(&renderer->m_ResourceCache, clayId);
+    if (!l_Texture)
+    {
+        return;
+    }
+
+    l_Texture->m_ImageView = imageView;
+    l_Texture->m_Sampler = sampler;
+    l_Texture->m_DescriptorSet = descriptorSet;
+}
+
+// Future improvements -------------------------------------------------------
+// - Descriptor recycling: shrink transient allocations by pooling VkDescriptorSet objects per frame.
+// - Dynamic rendering: replace render pass dependency with vkCmdBeginRendering for more flexible swapchain formats.
+// - Batching: group adjacent rectangles or text quads into large instance draws using secondary command buffers.