Revert "Revert "Add integer texture support.""

This reverts commit 9c7edb8311409a141b0dc1d5e480c68c629f1997.

Fixes ASAN errors

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4736

Change-Id: I1b1dae754d357b01da7169c8e7c59d7d8d8a10f6
Reviewed-on: https://skia-review.googlesource.com/4736
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 51 insertions, 11 deletions

diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index a37d0e093f..ed3c38180e 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -863,6 +863,10 @@ bool GrGLCaps::readPixelsSupported(GrPixelConfig surfaceConfig,
         return false;
     }
 
+    if (GrPixelConfigIsSint(surfaceConfig) != GrPixelConfigIsSint(readConfig)) {
+        return false;
+    }
+
     GrGLenum readFormat;
     GrGLenum readType;
     if (!this->getReadPixelsFormat(surfaceConfig, readConfig, &readFormat, &readType)) {
@@ -874,8 +878,11 @@ bool GrGLCaps::readPixelsSupported(GrPixelConfig surfaceConfig,
         // the manual (https://www.opengl.org/sdk/docs/man/) says only these formats are allowed:
         // GL_STENCIL_INDEX, GL_DEPTH_COMPONENT, GL_DEPTH_STENCIL, GL_RED, GL_GREEN, GL_BLUE,
         // GL_RGB, GL_BGR, GL_RGBA, and GL_BGRA. We check for the subset that we would use.
+        // The manual does not seem to fully match the spec as the spec allows integer formats
+        // when the bound color buffer is an integer buffer. It doesn't specify which integer
+        // formats are allowed, so perhaps all of them are. We only use GL_RGBA_INTEGER currently.
         if (readFormat != GR_GL_RED && readFormat != GR_GL_RGB && readFormat != GR_GL_RGBA &&
-            readFormat != GR_GL_BGRA) {
+            readFormat != GR_GL_BGRA && readFormat != GR_GL_RGBA_INTEGER) {
             return false;
         }
         // There is also a set of allowed types, but all the types we use are in the set:
@@ -890,16 +897,22 @@ bool GrGLCaps::readPixelsSupported(GrPixelConfig surfaceConfig,
     }
 
     // See Section 16.1.2 in the ES 3.2 specification.
-
-    if (kNormalizedFixedPoint_FormatType == fConfigTable[surfaceConfig].fFormatType) {
-        if (GR_GL_RGBA == readFormat && GR_GL_UNSIGNED_BYTE == readType) {
-            return true;
-        }
-    } else {
-        SkASSERT(kFloat_FormatType == fConfigTable[surfaceConfig].fFormatType);
-        if (GR_GL_RGBA == readFormat && GR_GL_FLOAT == readType) {
-            return true;
-        }
+    switch (fConfigTable[surfaceConfig].fFormatType) {
+        case kNormalizedFixedPoint_FormatType:
+            if (GR_GL_RGBA == readFormat && GR_GL_UNSIGNED_BYTE == readType) {
+                return true;
+            }
+            break;
+        case kInteger_FormatType:
+            if (GR_GL_RGBA_INTEGER == readFormat && GR_GL_INT == readType) {
+                return true;
+            }
+            break;
+        case kFloat_FormatType:
+            if (GR_GL_RGBA == readFormat && GR_GL_FLOAT == readType) {
+                return true;
+            }
+            break;
     }
 
     if (0 == fConfigTable[surfaceConfig].fSecondReadPixelsFormat.fFormat) {
@@ -1569,6 +1582,33 @@ void GrGLCaps::initConfigTable(const GrGLContextInfo& ctxInfo, const GrGLInterfa
     }
     fConfigTable[kSBGRA_8888_GrPixelConfig].fSwizzle = GrSwizzle::RGBA();
 
+    bool hasIntegerTextures;
+    if (standard == kGL_GrGLStandard) {
+        hasIntegerTextures = version >= GR_GL_VER(3, 0) ||
+                             ctxInfo.hasExtension("GL_EXT_texture_integer");
+    } else {
+        hasIntegerTextures = (version >= GR_GL_VER(3, 0));
+    }
+    // We may have limited GLSL to an earlier version that doesn't have integer sampler types.
+    if (ctxInfo.glslGeneration() == k110_GrGLSLGeneration) {
+        hasIntegerTextures = false;
+    }
+    fConfigTable[kRGBA_8888_sint_GrPixelConfig].fFormats.fBaseInternalFormat  = GR_GL_RGBA_INTEGER;
+    fConfigTable[kRGBA_8888_sint_GrPixelConfig].fFormats.fSizedInternalFormat = GR_GL_RGBA8I;
+    fConfigTable[kRGBA_8888_sint_GrPixelConfig].fFormats.fExternalFormat[kOther_ExternalFormatUsage] = GR_GL_RGBA_INTEGER;
+    fConfigTable[kRGBA_8888_sint_GrPixelConfig].fFormats.fExternalType = GR_GL_BYTE;
+    fConfigTable[kRGBA_8888_sint_GrPixelConfig].fFormatType = kInteger_FormatType;
+    // We currently only support using integer textures as srcs, not for rendering (even though GL
+    // allows it).
+    if (hasIntegerTextures) {
+        fConfigTable[kRGBA_8888_sint_GrPixelConfig].fFlags = ConfigInfo::kTextureable_Flag |
+                                                             ConfigInfo::kFBOColorAttachment_Flag;
+        if (texStorageSupported) {
+            fConfigTable[kRGBA_8888_sint_GrPixelConfig].fFlags |=
+                ConfigInfo::kCanUseTexStorage_Flag;
+        }
+    }
+
     fConfigTable[kRGB_565_GrPixelConfig].fFormats.fBaseInternalFormat = GR_GL_RGB;
     if (this->ES2CompatibilitySupport()) {
         fConfigTable[kRGB_565_GrPixelConfig].fFormats.fSizedInternalFormat = GR_GL_RGB565;