vulkan: Only draw one rect

Instead of emitting the render commands once per rectangle of the clip
region, just emit them once with the region's extents.

This is generally faster because it emits fewer commands to the GPU,
even though it may touch significantly more pixels.

For a proper method, we'd need to record the commands per clip rectangle
instead of emitting all of them all the time.

diff --git a/gsk/vulkan/gskvulkanrenderpass.c b/gsk/vulkan/gskvulkanrenderpass.c
index 4004570029e57fe4bc89d9205a41341df6e0eadb..223ee00e78ce36d8e824a2461b3d549410444526 100644 (file)
--- a/gsk/vulkan/gskvulkanrenderpass.c
+++ b/gsk/vulkan/gskvulkanrenderpass.c
@@ -2410,7 +2410,7 @@ gsk_vulkan_render_pass_draw (GskVulkanRenderPass *self,
                              VkPipelineLayout     pipeline_layout,
                              VkCommandBuffer      command_buffer)
 {
-  guint i;
+  cairo_rectangle_int_t rect;
 
   vkCmdSetViewport (command_buffer,
                     0,
@@ -2424,38 +2424,33 @@ gsk_vulkan_render_pass_draw (GskVulkanRenderPass *self,
                         .maxDepth = 1
                     });
 
-  for (i = 0; i < cairo_region_num_rectangles (self->clip); i++)
-    {
-      cairo_rectangle_int_t rect;
-
-      cairo_region_get_rectangle (self->clip, i, &rect);
-
-      vkCmdSetScissor (command_buffer,
-                       0,
-                       1,
-                       &(VkRect2D) {
-                          { rect.x, rect.y },
-                          { rect.width, rect.height }
-                       });
-
-      vkCmdBeginRenderPass (command_buffer,
-                            &(VkRenderPassBeginInfo) {
-                                .sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO,
-                                .renderPass = self->render_pass,
-                                .framebuffer = gsk_vulkan_render_get_framebuffer (render, self->target),
-                                .renderArea = { 
-                                    { rect.x, rect.y },
-                                    { rect.width, rect.height }
-                                },
-                                .clearValueCount = 1,
-                                .pClearValues = (VkClearValue [1]) {
-                                    { .color = { .float32 = { 0.f, 0.f, 0.f, 0.f } } }
-                                }
+  cairo_region_get_extents (self->clip, &rect);
+
+  vkCmdSetScissor (command_buffer,
+                   0,
+                   1,
+                   &(VkRect2D) {
+                      { rect.x, rect.y },
+                      { rect.width, rect.height }
+                   });
+
+  vkCmdBeginRenderPass (command_buffer,
+                        &(VkRenderPassBeginInfo) {
+                            .sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO,
+                            .renderPass = self->render_pass,
+                            .framebuffer = gsk_vulkan_render_get_framebuffer (render, self->target),
+                            .renderArea = { 
+                                { rect.x, rect.y },
+                                { rect.width, rect.height }
                             },
-                            VK_SUBPASS_CONTENTS_INLINE);
+                            .clearValueCount = 1,
+                            .pClearValues = (VkClearValue [1]) {
+                                { .color = { .float32 = { 0.f, 0.f, 0.f, 0.f } } }
+                            }
+                        },
+                        VK_SUBPASS_CONTENTS_INLINE);
 
-      gsk_vulkan_render_pass_draw_rect (self, render, pipeline_layout, command_buffer);
+  gsk_vulkan_render_pass_draw_rect (self, render, pipeline_layout, command_buffer);
 
-      vkCmdEndRenderPass (command_buffer);
-    }
+  vkCmdEndRenderPass (command_buffer);
 }