Merge branch 'allcreater-gl_texture_cache_fix'

2 files changed, 16 insertions, 6 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 396ddc75..9fc029a9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 ## Updates
 
+- **15-Feb-2023**: A fix in the sokol_gfx.h GL backend: due to a bug in the
+  state cache, the GL backend could only bind a total of
+  SG_MAX_SHADERSTAGE_IMAGES (= 12) when it actually should be twice that amount
+  (12 per shader stage). Note however that the total amount of texture bindings
+  is still internally limited by the GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS
+  runtime variable (currently this is not exposed in sg_limits though). Many
+  thanks to @allcreater for PR https://github.com/floooh/sokol/pull/787.
+
 - **13-Feb-2023**: The way logging works has been completely revamped in
   the sokol headers. UWP support has been removed from sokol_audio.h
   and sokol_app.h (this also means that the sokol headers no longer contain
diff --git a/sokol_gfx.h b/sokol_gfx.h
index 33ad91d4..c799baaa 100644
--- a/sokol_gfx.h
+++ b/sokol_gfx.h
@@ -4069,6 +4069,8 @@ typedef struct {
     GLuint texture;
 } _sg_gl_texture_bind_slot;
 
+#define _SG_GL_IMAGE_CACHE_SIZE (SG_MAX_SHADERSTAGE_IMAGES * SG_NUM_SHADER_STAGES)
+
 typedef struct {
     sg_depth_state depth;
     sg_stencil_state stencil;
@@ -4086,7 +4088,7 @@ typedef struct {
     GLuint stored_vertex_buffer;
     GLuint stored_index_buffer;
     GLuint prog;
-    _sg_gl_texture_bind_slot textures[SG_MAX_SHADERSTAGE_IMAGES];
+    _sg_gl_texture_bind_slot textures[_SG_GL_IMAGE_CACHE_SIZE];
     _sg_gl_texture_bind_slot stored_texture;
     int cur_ib_offset;
     GLenum cur_primitive_type;
@@ -6719,7 +6721,7 @@ _SOKOL_PRIVATE void _sg_gl_cache_active_texture(GLenum texture) {
 }
 
 _SOKOL_PRIVATE void _sg_gl_cache_clear_texture_bindings(bool force) {
-    for (int i = 0; (i < SG_MAX_SHADERSTAGE_IMAGES) && (i < _sg.gl.max_combined_texture_image_units); i++) {
+    for (int i = 0; (i < _SG_GL_IMAGE_CACHE_SIZE) && (i < _sg.gl.max_combined_texture_image_units); i++) {
         if (force || (_sg.gl.cache.textures[i].texture != 0)) {
             GLenum gl_texture_slot = (GLenum) (GL_TEXTURE0 + i);
             glActiveTexture(gl_texture_slot);
@@ -6743,7 +6745,7 @@ _SOKOL_PRIVATE void _sg_gl_cache_bind_texture(int slot_index, GLenum target, GLu
        target=0 will unbind the previous binding, texture=0 will clear
        the new binding
     */
-    SOKOL_ASSERT(slot_index < SG_MAX_SHADERSTAGE_IMAGES);
+    SOKOL_ASSERT((slot_index >= 0) && (slot_index < _SG_GL_IMAGE_CACHE_SIZE));
     if (slot_index >= _sg.gl.max_combined_texture_image_units) {
         return;
     }
@@ -6764,12 +6766,12 @@ _SOKOL_PRIVATE void _sg_gl_cache_bind_texture(int slot_index, GLenum target, GLu
 }
 
 _SOKOL_PRIVATE void _sg_gl_cache_store_texture_binding(int slot_index) {
-    SOKOL_ASSERT(slot_index < SG_MAX_SHADERSTAGE_IMAGES);
+    SOKOL_ASSERT((slot_index >= 0) && (slot_index < _SG_GL_IMAGE_CACHE_SIZE));
     _sg.gl.cache.stored_texture = _sg.gl.cache.textures[slot_index];
 }
 
 _SOKOL_PRIVATE void _sg_gl_cache_restore_texture_binding(int slot_index) {
-    SOKOL_ASSERT(slot_index < SG_MAX_SHADERSTAGE_IMAGES);
+    SOKOL_ASSERT((slot_index >= 0) && (slot_index < _SG_GL_IMAGE_CACHE_SIZE));
     _sg_gl_texture_bind_slot* slot = &_sg.gl.cache.stored_texture;
     if (slot->texture != 0) {
         /* we only care restoring valid ids */
@@ -6782,7 +6784,7 @@ _SOKOL_PRIVATE void _sg_gl_cache_restore_texture_binding(int slot_index) {
 
 /* called from _sg_gl_destroy_texture() */
 _SOKOL_PRIVATE void _sg_gl_cache_invalidate_texture(GLuint tex) {
-    for (int i = 0; i < SG_MAX_SHADERSTAGE_IMAGES; i++) {
+    for (int i = 0; i < _SG_GL_IMAGE_CACHE_SIZE; i++) {
         _sg_gl_texture_bind_slot* slot = &_sg.gl.cache.textures[i];
         if (tex == slot->texture) {
             _sg_gl_cache_active_texture((GLenum)(GL_TEXTURE0 + i));