GPU: refactor clipped drawing from DRW into GPU

Needed to fix T61196, supporting clipped back-buffer in the 3D view
which is done outside the draw module.

It was also inconvenient having DRW_shader_* versions of GPU_shader_*
API calls.

- Clipping distances are now supported as a shader configuration
  for builtin shaders.
- Add shader config argument when accessing builtin shaders.
- Move GPU_shader_create_from_arrays() from DRW to GPU.

1 files changed, 18 insertions, 3 deletions

diff --git a/source/blender/gpu/GPU_shader.h b/source/blender/gpu/GPU_shader.h
index d2380d27464..428c7634195 100644
--- a/source/blender/gpu/GPU_shader.h
+++ b/source/blender/gpu/GPU_shader.h
@@ -60,6 +60,12 @@ GPUShader *GPU_shader_create_ex(
         const char **tf_names,
         const int tf_count,
         const char *shader_name);
+struct GPU_ShaderCreateFromArray_Params { const char **vert, **geom, **frag, **defs; };
+struct GPUShader *GPU_shader_create_from_arrays_impl(
+        const struct GPU_ShaderCreateFromArray_Params *params);
+#define GPU_shader_create_from_arrays(...) \
+	GPU_shader_create_from_arrays_impl(&(const struct GPU_ShaderCreateFromArray_Params)__VA_ARGS__)
+
 void GPU_shader_free(GPUShader *shader);
 
 void GPU_shader_bind(GPUShader *shader);
@@ -350,9 +356,15 @@ typedef enum eGPUBuiltinShader {
 	/* Selection */
 	GPU_SHADER_3D_FLAT_SELECT_ID,
 	GPU_SHADER_3D_UNIFORM_SELECT_ID,
-
-	GPU_NUM_BUILTIN_SHADERS /* (not an actual shader) */
 } eGPUBuiltinShader;
+#define GPU_SHADER_BUILTIN_LEN (GPU_SHADER_3D_UNIFORM_SELECT_ID + 1)
+
+/** Support multiple configurations. */
+typedef enum eGPUShaderConfig {
+	GPU_SHADER_CFG_DEFAULT     = 0,
+	GPU_SHADER_CFG_CLIPPED     = 1,
+} eGPUShaderConfig;
+#define GPU_SHADER_CFG_LEN (GPU_SHADER_CFG_CLIPPED + 1)
 
 /** Keep these in sync with:
  * - `gpu_shader_image_interlace_frag.glsl`
@@ -364,7 +376,10 @@ typedef enum eGPUInterlaceShader {
 	GPU_SHADER_INTERLACE_CHECKER           = 2,
 } eGPUInterlaceShader;
 
-GPUShader *GPU_shader_get_builtin_shader(eGPUBuiltinShader shader);
+GPUShader *GPU_shader_get_builtin_shader_with_config(
+        eGPUBuiltinShader shader, eGPUShaderConfig shader_cfg);
+GPUShader *GPU_shader_get_builtin_shader(
+        eGPUBuiltinShader shader);
 
 void GPU_shader_get_builtin_shader_code(
         eGPUBuiltinShader shader,