Fix viewport w and h error.

Author: ChillingVan

canvasgl/src/main/java/com/chillingvan/canvasgl/ICanvasGL.java

@@ -26,9 +26,6 @@
 import android.graphics.SurfaceTexture;
 import android.opengl.GLES20;
 import android.opengl.Matrix;
-import androidx.annotation.IntRange;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 
 import com.chillingvan.canvasgl.glcanvas.BasicTexture;
 import com.chillingvan.canvasgl.glcanvas.BitmapTexture;
@@ -40,6 +37,10 @@
 import com.chillingvan.canvasgl.matrix.IBitmapMatrix;
 import com.chillingvan.canvasgl.textureFilter.TextureFilter;
 
+import androidx.annotation.IntRange;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 /**
  * Created by Matthew on 2016/9/26.
  */
@@ -197,7 +198,7 @@ public float[] obtainResultMatrix(int viewportW, int viewportH, float x, float y
             final float absTransY = Math.abs(transform[TRANSLATE_Y]); // Make sure realViewportH - viewportY includes viewportH
             int realViewportW = (int) (viewPortRatio * viewportW + 2*absTransX);
             int realViewportH = (int) (viewPortRatio * viewportH + 2*absTransY);
-            realViewportW = Math.max(realViewportW, maxViewPortInt);
+            realViewportW = Math.min(realViewportW, maxViewPortInt);
             realViewportH = Math.min(realViewportH, maxViewPortInt);
             int viewportX = (int) (drawW / 2 - realViewportW / 2 + transform[TRANSLATE_X]);
             int viewportY = (int) (-drawH / 2 - transform[TRANSLATE_Y] - realViewportH / 2 + viewportH);

canvasgl/src/main/java/com/chillingvan/canvasgl/glcanvas/GLES20Canvas.java

@@ -555,11 +555,11 @@ private void draw(ShaderParameter[] params, int type, int count, float x, float
 
     private void setMatrix(ShaderParameter[] params, float x, float y, float width, float height, ICustomMVPMatrix customMVPMatrix) {
         if (customMVPMatrix != null) {
-            GLES20.glUniformMatrix4fv(params[INDEX_MATRIX].handle, 1, false, customMVPMatrix.getMVPMatrix(mScreenWidth, mScreenHeight, x, y, width, height), 0);
+            GLES20.glUniformMatrix4fv(params[INDEX_MATRIX].handle, 1, false, customMVPMatrix.getMVPMatrix(mWidth, mHeight, x, y, width, height), 0);
             checkError();
             return;
         }
-        GLES20.glViewport(0, 0, mScreenWidth, mScreenHeight);
+        GLES20.glViewport(0, 0, mWidth, mHeight);
         Matrix.translateM(mTempMatrix, 0, mMatrices, mCurrentMatrixIndex, x, y, 0f);
         Matrix.scaleM(mTempMatrix, 0, width, height, 1f);
         Matrix.multiplyMM(mTempMatrix, MATRIX_SIZE, mProjectionMatrix, 0, mTempMatrix, 0);