GPU: Texture: Replace internal sampler state by explicit state object

This makes it easier to track as well as allowing us to sample the same
texture with different sampling parameters (which should fix the related
T73942 in the long run).

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D7831

1 files changed, 25 insertions, 0 deletions

diff --git a/source/blender/gpu/GPU_texture.h b/source/blender/gpu/GPU_texture.h
index 3d99a3c8a56..a1e00793857 100644
--- a/source/blender/gpu/GPU_texture.h
+++ b/source/blender/gpu/GPU_texture.h
@@ -41,6 +41,31 @@ struct PreviewImage;
 struct GPUFrameBuffer;
 typedef struct GPUTexture GPUTexture;
 
+/* GPU Samplers state
+ * - Specify the sampler state to bind a texture with.
+ * - Internally used by textures.
+ * - All states are created at startup to avoid runtime costs.
+ */
+
+typedef enum eGPUSamplerState {
+  GPU_SAMPLER_FILTER = (1 << 0),
+  GPU_SAMPLER_MIPMAP = (1 << 1),
+  GPU_SAMPLER_REPEAT_S = (1 << 2),
+  GPU_SAMPLER_REPEAT_T = (1 << 3),
+  GPU_SAMPLER_REPEAT_R = (1 << 4),
+  GPU_SAMPLER_CLAMP_BORDER = (1 << 5), /* Clamp to border color instead of border texel. */
+  GPU_SAMPLER_COMPARE = (1 << 6),
+  GPU_SAMPLER_ANISO = (1 << 7),
+  /* Don't use that. */
+  GPU_SAMPLER_MAX = (1 << 8),
+} eGPUSamplerState;
+
+#define GPU_SAMPLER_DEFAULT GPU_SAMPLER_FILTER
+#define GPU_SAMPLER_REPEAT (GPU_SAMPLER_REPEAT_S | GPU_SAMPLER_REPEAT_T | GPU_SAMPLER_REPEAT_R)
+
+void GPU_samplers_init(void);
+void GPU_samplers_free(void);
+
 /* GPU Texture
  * - always returns unsigned char RGBA textures
  * - if texture with non square dimensions is created, depending on the