GPU: Create and use new GPU_texture_read_rect utility.

2 files changed, 32 insertions, 0 deletions

diff --git a/source/blender/gpu/GPU_texture.h b/source/blender/gpu/GPU_texture.h
index e596fe9256e..18cf3dc4ced 100644
--- a/source/blender/gpu/GPU_texture.h
+++ b/source/blender/gpu/GPU_texture.h
@@ -185,6 +185,9 @@ void GPU_texture_update_sub(
         int offset_x, int offset_y, int offset_z, int width, int height, int depth);
 
 void *GPU_texture_read(GPUTexture *tex, eGPUDataFormat gpu_data_format, int miplvl);
+void GPU_texture_read_rect(
+        GPUTexture *tex, eGPUDataFormat gpu_data_format,
+        const struct rcti *rect, void *r_buf);
 
 void GPU_invalid_tex_init(void);
 void GPU_invalid_tex_bind(int mode);
diff --git a/source/blender/gpu/intern/gpu_texture.c b/source/blender/gpu/intern/gpu_texture.c
index ebb7b4bc0f0..e2aa26c3b33 100644
--- a/source/blender/gpu/intern/gpu_texture.c
+++ b/source/blender/gpu/intern/gpu_texture.c
@@ -1266,6 +1266,35 @@ void *GPU_texture_read(GPUTexture *tex, eGPUDataFormat gpu_data_format, int mipl
 	return buf;
 }
 
+void GPU_texture_read_rect(
+        GPUTexture *tex, eGPUDataFormat gpu_data_format,
+        const rcti *rect, void *r_buf)
+{
+	gpu_validate_data_format(tex->format, gpu_data_format);
+
+	GPUFrameBuffer *cur_fb = GPU_framebuffer_active_get();
+	GPUFrameBuffer *tmp_fb = GPU_framebuffer_create();
+	GPU_framebuffer_texture_attach(tmp_fb, tex, 0, 0);
+
+	GPU_framebuffer_bind(tmp_fb);
+	glReadBuffer(GL_COLOR_ATTACHMENT0);
+
+	GLenum data_format = gpu_get_gl_dataformat(tex->format, &tex->format_flag);
+	GLenum data_type = gpu_get_gl_datatype(gpu_data_format);
+
+	glReadPixels(rect->xmin, rect->ymin,
+	             BLI_rcti_size_x(rect), BLI_rcti_size_y(rect),
+	             data_format, data_type, r_buf);
+
+	if (cur_fb) {
+		GPU_framebuffer_bind(cur_fb);
+	}
+	else {
+		GPU_framebuffer_restore();
+	}
+	GPU_framebuffer_free(tmp_fb);
+}
+
 void GPU_texture_update(GPUTexture *tex, eGPUDataFormat data_format, const void *pixels)
 {
 	GPU_texture_update_sub(tex, data_format, pixels, 0, 0, 0, tex->w, tex->h, tex->d);