Cleanup: GPU: Replace all glReadPixels by GPU equivalent

source/blender/draw/engines/eevee/eevee_lut_gen.c

@@ -76,7 +76,7 @@ static struct GPUTexture *create_ggx_lut_texture(int UNUSED(w), int UNUSED(h))
   DRW_draw_pass(pass);
 
   float *data = MEM_mallocN(sizeof(float[3]) * w * h, "lut");
-  GPU_framebuffer_read_color(fb, 0, 0, w, h, 3, 0, data);
+  GPU_framebuffer_read_color(fb, 0, 0, w, h, 3, 0, GPU_DATA_FLOAT, data);
 
   printf("{");
   for (int i = 0; i < w * h * 3; i += 3) {

source/blender/draw/engines/eevee/eevee_render.c

@@ -267,6 +267,7 @@ static void eevee_render_color_result(RenderLayer *rl,
                              BLI_rcti_size_y(rect),
                              num_channels,
                              0,
+                             GPU_DATA_FLOAT,
                              rp->rect);
 }
 

source/blender/draw/engines/gpencil/gpencil_render.c

@@ -235,6 +235,7 @@ static void GPENCIL_render_result_combined(struct RenderLayer *rl,
                              BLI_rcti_size_y(rect),
                              4,
                              0,
+                             GPU_DATA_FLOAT,
                              rp->rect);
 }
 

source/blender/draw/engines/workbench/workbench_render.c

@@ -212,6 +212,7 @@ void workbench_render(void *ved, RenderEngine *engine, RenderLayer *render_layer
                              BLI_rcti_size_y(rect),
                              4,
                              0,
+                             GPU_DATA_FLOAT,
                              rp->rect);
 
   workbench_render_result_z(render_layer, viewname, rect);

source/blender/draw/intern/draw_hair.c

@@ -343,7 +343,7 @@ void DRW_hair_update(void)
 
       DRW_draw_pass_subset(g_tf_pass, pr_call->shgrp, pr_call->shgrp);
       /* Readback result to main memory. */
-      GPU_framebuffer_read_color(fb, 0, 0, width, height, 4, 0, data);
+      GPU_framebuffer_read_color(fb, 0, 0, width, height, 4, 0, GPU_DATA_FLOAT, data);
       /* Upload back to VBO. */
       GPU_vertbuf_use(pr_call->vbo);
       glBufferSubData(GL_ARRAY_BUFFER,

source/blender/draw/intern/draw_select_buffer.c

@@ -84,13 +84,14 @@ uint *DRW_select_buffer_read(struct Depsgraph *depsgraph,
 
       GPUFrameBuffer *select_id_fb = DRW_engine_select_framebuffer_get();
       GPU_framebuffer_bind(select_id_fb);
-      glReadBuffer(GL_COLOR_ATTACHMENT0);
+      GPU_framebuffer_read_color(select_id_fb,
-      glReadPixels(rect_clamp.xmin,
+                                 rect_clamp.xmin,
                                  rect_clamp.ymin,
                                  BLI_rcti_size_x(&rect_clamp),
                                  BLI_rcti_size_y(&rect_clamp),
-                   GL_RED_INTEGER,
+                                 1,
-                   GL_UNSIGNED_INT,
+                                 0,
+                                 GPU_DATA_UNSIGNED_INT,
                                  r_buf);
 
       if (!BLI_rcti_compare(rect, &rect_clamp)) {

source/blender/editors/sculpt_paint/paint_utils.c

@@ -55,9 +55,10 @@
 #include "RNA_access.h"
 #include "RNA_define.h"
 
-#include "GPU_glew.h"
+#include "GPU_framebuffer.h"
 #include "GPU_matrix.h"
 #include "GPU_state.h"
+#include "GPU_texture.h"
 
 #include "IMB_colormanagement.h"
 #include "IMB_imbuf.h"
@@ -246,7 +247,7 @@ static void imapaint_project(float matrix[4][4], const float co[3], float pco[4]
 }
 
 static void imapaint_tri_weights(float matrix[4][4],
-                                 const GLint view[4],
+                                 const int view[4],
                                  const float v1[3],
                                  const float v2[3],
                                  const float v3[3],
@@ -300,7 +301,7 @@ static void imapaint_pick_uv(
   int i, findex;
   float p[2], w[3], absw, minabsw;
   float matrix[4][4], proj[4][4];
-  GLint view[4];
+  int view[4];
   const eImagePaintMode mode = scene->toolsettings->imapaint.mode;
 
   const MLoopTri *lt = BKE_mesh_runtime_looptri_ensure(me_eval);
@@ -576,20 +577,16 @@ void paint_sample_color(
     }
 
     if (!sample_success) {
-      glReadBuffer(GL_FRONT);
+      GPU_frontbuffer_read_pixels(
-      glReadPixels(
+          x + region->winrct.xmin, y + region->winrct.ymin, 1, 1, 4, GPU_DATA_UNSIGNED_BYTE, &col);
-          x + region->winrct.xmin, y + region->winrct.ymin, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &col);
-      glReadBuffer(GL_BACK);
     }
     else {
       return;
     }
   }
   else {
-    glReadBuffer(GL_FRONT);
+    GPU_frontbuffer_read_pixels(
-    glReadPixels(
+        x + region->winrct.xmin, y + region->winrct.ymin, 1, 1, 4, GPU_DATA_UNSIGNED_BYTE, &col);
-        x + region->winrct.xmin, y + region->winrct.ymin, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &col);
-    glReadBuffer(GL_BACK);
   }
   cp = (uchar *)&col;
 

source/blender/gpu/GPU_framebuffer.h

@@ -28,7 +28,7 @@
 extern "C" {
 #endif
 
-struct GPUTexture;
+#include "GPU_texture.h"
 
 typedef struct GPUAttachment {
   struct GPUTexture *tex;
@@ -176,8 +176,15 @@ void GPU_framebuffer_clear(GPUFrameBuffer *fb,
 void GPU_framebuffer_multi_clear(GPUFrameBuffer *fb, const float (*clear_cols)[4]);
 
 void GPU_framebuffer_read_depth(GPUFrameBuffer *fb, int x, int y, int w, int h, float *data);
-void GPU_framebuffer_read_color(
+void GPU_framebuffer_read_color(GPUFrameBuffer *fb,
-    GPUFrameBuffer *fb, int x, int y, int w, int h, int channels, int slot, float *data);
+                                int x,
+                                int y,
+                                int w,
+                                int h,
+                                int channels,
+                                int slot,
+                                eGPUDataFormat format,
+                                void *data);
 
 void GPU_framebuffer_blit(GPUFrameBuffer *fb_read,
                           int read_slot,
@@ -214,6 +221,9 @@ void GPU_clear_color(float red, float green, float blue, float alpha);
 void GPU_clear_depth(float depth);
 void GPU_clear(eGPUFrameBufferBits flags);
 
+void GPU_frontbuffer_read_pixels(
+    int x, int y, int w, int h, int channels, eGPUDataFormat format, void *data);
+
 #ifdef __cplusplus
 }
 #endif

source/blender/gpu/intern/gpu_framebuffer.c

@@ -640,31 +640,65 @@ void GPU_framebuffer_read_depth(GPUFrameBuffer *fb, int x, int y, int w, int h,
   glReadPixels(x, y, w, h, type, GL_FLOAT, data);
 }
 
-void GPU_framebuffer_read_color(
+static GLenum gpu_get_gl_datatype(eGPUDataFormat format)
-    GPUFrameBuffer *fb, int x, int y, int w, int h, int channels, int slot, float *data)
 {
-  CHECK_FRAMEBUFFER_IS_BOUND(fb);
+  switch (format) {
+    case GPU_DATA_FLOAT:
+      return GL_FLOAT;
+    case GPU_DATA_INT:
+      return GL_INT;
+    case GPU_DATA_UNSIGNED_INT:
+      return GL_UNSIGNED_INT;
+    case GPU_DATA_UNSIGNED_BYTE:
+      return GL_UNSIGNED_BYTE;
+    case GPU_DATA_UNSIGNED_INT_24_8:
+      return GL_UNSIGNED_INT_24_8;
+    case GPU_DATA_10_11_11_REV:
+      return GL_UNSIGNED_INT_10F_11F_11F_REV;
+    default:
+      BLI_assert(!"Unhandled data format");
+      return GL_FLOAT;
+  }
+}
 
-  GLenum type;
+static GLenum gpu_get_gl_channel_type(int channels)
+{
   switch (channels) {
     case 1:
-      type = GL_RED;
+      return GL_RED;
-      break;
     case 2:
-      type = GL_RG;
+      return GL_RG;
-      break;
     case 3:
-      type = GL_RGB;
+      return GL_RGB;
-      break;
     case 4:
-      type = GL_RGBA;
+      return GL_RGBA;
-      break;
     default:
-      BLI_assert(false && "wrong number of read channels");
+      BLI_assert(!"Wrong number of read channels");
-      return;
+      return GL_RED;
   }
-  glReadBuffer(GL_COLOR_ATTACHMENT0 + slot);
+}
-  glReadPixels(x, y, w, h, type, GL_FLOAT, data);
+
+static void gpu_framebuffer_read_color_ex(
+    int x, int y, int w, int h, int channels, GLenum readfb, eGPUDataFormat format, float *data)
+{
+  GLenum type = gpu_get_gl_channel_type(channels);
+  GLenum gl_format = gpu_get_gl_datatype(format);
+  glReadBuffer(readfb);
+  glReadPixels(x, y, w, h, type, gl_format, data);
+}
+
+void GPU_framebuffer_read_color(GPUFrameBuffer *fb,
+                                int x,
+                                int y,
+                                int w,
+                                int h,
+                                int channels,
+                                int slot,
+                                eGPUDataFormat format,
+                                void *data)
+{
+  CHECK_FRAMEBUFFER_IS_BOUND(fb);
+  gpu_framebuffer_read_color_ex(x, y, w, h, channels, GL_COLOR_ATTACHMENT0 + slot, format, data);
 }
 
 /* read_slot and write_slot are only used for color buffers. */
@@ -749,9 +783,9 @@ void GPU_framebuffer_blit(GPUFrameBuffer *fb_read,
 }
 
 /**
- * Use this if you need to custom down-sample your texture and use the previous mip level as input.
+ * Use this if you need to custom down-sample your texture and use the previous mip level as
- * This function only takes care of the correct texture handling.
+ * input. This function only takes care of the correct texture handling. It execute the callback
- * It execute the callback for each texture level.
+ * for each texture level.
  */
 void GPU_framebuffer_recursive_downsample(GPUFrameBuffer *fb,
                                           int max_lvl,
@@ -1035,3 +1069,10 @@ void GPU_clear(eGPUFrameBufferBits flags)
 {
   glClear(convert_buffer_bits_to_gl(flags));
 }
+
+void GPU_frontbuffer_read_pixels(
+    int x, int y, int w, int h, int channels, eGPUDataFormat format, void *data)
+{
+  glReadBuffer(GL_FRONT);
+  gpu_framebuffer_read_color_ex(x, y, w, h, channels, GL_FRONT, format, data);
+}

source/blender/windowmanager/intern/wm_window.c

@@ -89,6 +89,7 @@
 #include "GPU_init_exit.h"
 #include "GPU_platform.h"
 #include "GPU_state.h"
+#include "GPU_texture.h"
 
 #include "UI_resources.h"
 
@@ -2054,9 +2055,7 @@ void WM_window_pixel_sample_read(const wmWindowManager *wm,
     GPU_context_active_set(win->gpuctx);
   }
 
-  glReadBuffer(GL_FRONT);
+  GPU_frontbuffer_read_pixels(pos[0], pos[1], 1, 1, 3, GPU_DATA_FLOAT, r_col);
-  glReadPixels(pos[0], pos[1], 1, 1, GL_RGB, GL_FLOAT, r_col);
-  glReadBuffer(GL_BACK);
 
   if (setup_context) {
     if (wm->windrawable) {
@@ -2089,10 +2088,7 @@ uint *WM_window_pixels_read(wmWindowManager *wm, wmWindow *win, int r_size[2])
   const uint rect_len = r_size[0] * r_size[1];
   uint *rect = MEM_mallocN(sizeof(*rect) * rect_len, __func__);
 
-  glReadBuffer(GL_FRONT);
+  GPU_frontbuffer_read_pixels(0, 0, r_size[0], r_size[1], 4, GPU_DATA_UNSIGNED_BYTE, rect);
-  glReadPixels(0, 0, r_size[0], r_size[1], GL_RGBA, GL_UNSIGNED_BYTE, rect);
-  glFinish();
-  glReadBuffer(GL_BACK);
 
   if (setup_context) {
     if (wm->windrawable) {