From 0d69f86e50e57afe893dade095c1dbd3d05c3b0f Mon Sep 17 00:00:00 2001 From: Andreas Müller Date: Wed, 29 Aug 2018 00:19:54 +0200 Subject: libsdl2: Fix left rotated display for RaspPi/VC4/GLES2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch should increase performance for libsdl2 on GLES2 too. Signed-off-by: Andreas Müller Signed-off-by: Richard Purdie --- ...01-GLES2-Get-sin-cos-out-of-vertex-shader.patch | 141 +++++++++++++++++++++ meta/recipes-graphics/libsdl2/libsdl2_2.0.8.bb | 1 + 2 files changed, 142 insertions(+) create mode 100644 meta/recipes-graphics/libsdl2/libsdl2/0001-GLES2-Get-sin-cos-out-of-vertex-shader.patch diff --git a/meta/recipes-graphics/libsdl2/libsdl2/0001-GLES2-Get-sin-cos-out-of-vertex-shader.patch b/meta/recipes-graphics/libsdl2/libsdl2/0001-GLES2-Get-sin-cos-out-of-vertex-shader.patch new file mode 100644 index 0000000000..3e9d1c6f34 --- /dev/null +++ b/meta/recipes-graphics/libsdl2/libsdl2/0001-GLES2-Get-sin-cos-out-of-vertex-shader.patch @@ -0,0 +1,141 @@ +From c215ba1d52a3d4ef03af3ab1a5baa1863f812aed Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Andreas=20M=C3=BCller?= +Date: Fri, 24 Aug 2018 23:10:25 +0200 +Subject: [PATCH] GLES2: Get sin/cos out of vertex shader +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +The only place angle is activated and causes effect is RenderCopyEx. All other +methods which use vertex shader, leave angle disabled and cause useless sin/cos +calculation in shader. + +To get around shader's interface is changed to a vector that contains results +of sin and cos. To behave properly when disabled, cos value is set with offset +-1.0 making 0.0 default when deactivated. + +As nice side effect it simplifies GLES2_UpdateVertexBuffer: All attributes are +vectors now. + +Additional background: + +* On RaspberryPi it gives a performace win for operations. Tested with + [1] numbers go down for 5-10% (not easy to estimate due to huge variation). +* SDL_RenderCopyEx was tested with [2] +* It works around left rotated display caused by low accuracy sin implemetation + in RaspberryPi/VC4 [3] + +Upstream-Status: Submitted [4] + +[1] https://github.com/schnitzeltony/sdl2box +[2] https://github.com/schnitzeltony/sdl2rendercopyex +[3] https://github.com/anholt/mesa/issues/110 +[4] https://hg.libsdl.org/SDL/rev/e5a666405750 + +Signed-off-by: Andreas Müller +--- + src/render/opengles2/SDL_render_gles2.c | 17 ++++++++++++----- + src/render/opengles2/SDL_shaders_gles2.c | 14 +++++++++----- + 2 files changed, 21 insertions(+), 10 deletions(-) + +diff --git a/src/render/opengles2/SDL_render_gles2.c b/src/render/opengles2/SDL_render_gles2.c +index 14671f7c8..7c54a7333 100644 +--- a/src/render/opengles2/SDL_render_gles2.c ++++ b/src/render/opengles2/SDL_render_gles2.c +@@ -1530,7 +1530,7 @@ GLES2_UpdateVertexBuffer(SDL_Renderer *renderer, GLES2_Attribute attr, + GLES2_DriverContext *data = (GLES2_DriverContext *)renderer->driverdata; + + #if !SDL_GLES2_USE_VBOS +- data->glVertexAttribPointer(attr, attr == GLES2_ATTRIBUTE_ANGLE ? 1 : 2, GL_FLOAT, GL_FALSE, 0, vertexData); ++ data->glVertexAttribPointer(attr, 2, GL_FLOAT, GL_FALSE, 0, vertexData); + #else + if (!data->vertex_buffers[attr]) { + data->glGenBuffers(1, &data->vertex_buffers[attr]); +@@ -1545,7 +1545,7 @@ GLES2_UpdateVertexBuffer(SDL_Renderer *renderer, GLES2_Attribute attr, + data->glBufferSubData(GL_ARRAY_BUFFER, 0, dataSizeInBytes, vertexData); + } + +- data->glVertexAttribPointer(attr, attr == GLES2_ATTRIBUTE_ANGLE ? 1 : 2, GL_FLOAT, GL_FALSE, 0, 0); ++ data->glVertexAttribPointer(attr, 2, GL_FLOAT, GL_FALSE, 0, 0); + #endif + + return 0; +@@ -1853,6 +1853,8 @@ GLES2_RenderCopy(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect *s + return GL_CheckError("", renderer); + } + ++#define PI 3.14159265f ++ + static int + GLES2_RenderCopyEx(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect *srcrect, + const SDL_FRect *dstrect, const double angle, const SDL_FPoint *center, const SDL_RendererFlip flip) +@@ -1861,8 +1863,9 @@ GLES2_RenderCopyEx(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect + GLfloat vertices[8]; + GLfloat texCoords[8]; + GLfloat translate[8]; +- GLfloat fAngle[4]; ++ GLfloat fAngle[8]; + GLfloat tmp; ++ float radian_angle; + + GLES2_ActivateRenderer(renderer); + +@@ -1872,7 +1875,11 @@ GLES2_RenderCopyEx(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect + + data->glEnableVertexAttribArray(GLES2_ATTRIBUTE_CENTER); + data->glEnableVertexAttribArray(GLES2_ATTRIBUTE_ANGLE); +- fAngle[0] = fAngle[1] = fAngle[2] = fAngle[3] = (GLfloat)(360.0f - angle); ++ ++ radian_angle = PI * (360.0f - angle) / 180.f; ++ fAngle[0] = fAngle[2] = fAngle[4] = fAngle[6] = (GLfloat)sin(radian_angle); ++ /* render expects cos value - 1 (see GLES2_VertexSrc_Default_) */ ++ fAngle[1] = fAngle[3] = fAngle[5] = fAngle[7] = (GLfloat)cos(radian_angle) - 1.0f; + /* Calculate the center of rotation */ + translate[0] = translate[2] = translate[4] = translate[6] = (center->x + dstrect->x); + translate[1] = translate[3] = translate[5] = translate[7] = (center->y + dstrect->y); +@@ -1901,7 +1908,7 @@ GLES2_RenderCopyEx(SDL_Renderer *renderer, SDL_Texture *texture, const SDL_Rect + data->glVertexAttribPointer(GLES2_ATTRIBUTE_CENTER, 2, GL_FLOAT, GL_FALSE, 0, translate); + data->glVertexAttribPointer(GLES2_ATTRIBUTE_POSITION, 2, GL_FLOAT, GL_FALSE, 0, vertices);*/ + +- GLES2_UpdateVertexBuffer(renderer, GLES2_ATTRIBUTE_ANGLE, fAngle, 4 * sizeof(GLfloat)); ++ GLES2_UpdateVertexBuffer(renderer, GLES2_ATTRIBUTE_ANGLE, fAngle, 8 * sizeof(GLfloat)); + GLES2_UpdateVertexBuffer(renderer, GLES2_ATTRIBUTE_CENTER, translate, 8 * sizeof(GLfloat)); + GLES2_UpdateVertexBuffer(renderer, GLES2_ATTRIBUTE_POSITION, vertices, 8 * sizeof(GLfloat)); + +diff --git a/src/render/opengles2/SDL_shaders_gles2.c b/src/render/opengles2/SDL_shaders_gles2.c +index b0bcdff25..f428a4945 100644 +--- a/src/render/opengles2/SDL_shaders_gles2.c ++++ b/src/render/opengles2/SDL_shaders_gles2.c +@@ -30,20 +30,24 @@ + /************************************************************************************************* + * Vertex/fragment shader source * + *************************************************************************************************/ +- ++/* Notes on a_angle: ++ * It is a vector containing sin and cos for rotation matrix ++ * To get correct rotation for most cases when a_angle is disabled cos ++ value is decremented by 1.0 to get proper output with 0.0 which is ++ default value ++*/ + static const Uint8 GLES2_VertexSrc_Default_[] = " \ + uniform mat4 u_projection; \ + attribute vec2 a_position; \ + attribute vec2 a_texCoord; \ +- attribute float a_angle; \ ++ attribute vec2 a_angle; \ + attribute vec2 a_center; \ + varying vec2 v_texCoord; \ + \ + void main() \ + { \ +- float angle = radians(a_angle); \ +- float c = cos(angle); \ +- float s = sin(angle); \ ++ float s = a_angle[0]; \ ++ float c = a_angle[1] + 1.0; \ + mat2 rotationMatrix = mat2(c, -s, s, c); \ + vec2 position = rotationMatrix * (a_position - a_center) + a_center; \ + v_texCoord = a_texCoord; \ +-- +2.14.4 + diff --git a/meta/recipes-graphics/libsdl2/libsdl2_2.0.8.bb b/meta/recipes-graphics/libsdl2/libsdl2_2.0.8.bb index accea38aaa..52bb93a17a 100644 --- a/meta/recipes-graphics/libsdl2/libsdl2_2.0.8.bb +++ b/meta/recipes-graphics/libsdl2/libsdl2_2.0.8.bb @@ -14,6 +14,7 @@ PROVIDES = "virtual/libsdl2" SRC_URI = "http://www.libsdl.org/release/SDL2-${PV}.tar.gz \ file://more-gen-depends.patch \ + file://0001-GLES2-Get-sin-cos-out-of-vertex-shader.patch \ " S = "${WORKDIR}/SDL2-${PV}" -- cgit 1.2.3-korg